I googled "star wars crafting" and this came up - repeatedly - in the results.

Puttin’ ‘em to work

The crafting/gathering system in Star Wars: The Old Republic is called the Crew Skills system, which confused a few people right off the bat when it was introduced. Your companions once again prove to be invaluable in SWTOR because they will do all your crafting for you – but you only have one general level for that skill across your entire crew, not a separate skill level for every crew member. And no, you yourself do not get to do any crafting – in fact, the only thing you can do for yourself is gather (a situation you can still work to your advantage even before getting a companion, as touched on by Zlatto’s Bazaar at Ask a Jedi the other day). There are a couple tasks for you, as well – such as Reverse Engineering, a concept everyone should really read about as it’s vital to getting better stuff for the crafting process - but for the most part, Crew Skills live up to their names, as it’s your crew doing the crafting.

1. You choose the schematic or schematics you wish to produce – up to about five items at a time – or the mission you wish to go on, whether it’s from a gathering or mission skill.
2. Choose the companion you want to perform the mission or craft – noting their bonuses (more on that in just a second).
3. Pay the nominal fee if you’re sending them on a gathering mission or mission skill mission – these are set so that you can’t just send a companion on infinite gathering or skill missions and vendor the results for constant profit.
4. Your companion vanishes to go craft the item or perform the mission. After a set period of time, they come back with rewards or the item you built.

There are some other interesting features with this companion-centric mode of crafting. For instance, if you see a gathering node in the world (be it a sliceable safe or a dead creature for bioanalysis), you can actually send your companion to gather it, without even needing to get into range to gather it yourself! You can even set that to be the default action when you right-click on a gatherable thing, thus never actually gathering anything yourself.

While any crew member can perform any crew skill with no penalty, most of them provide a bonus to an associated crew skill. Most of them are pretty straightforward – for instance, Mako, a slicer, has bonuses to slicing – but some are unexpected, such as T7-01 having a bonus to bioanalysis. SWTOR Spy has a full list of these bonuses!

A long time ago, in a job fair far, far away

So with that said, what are the Crew Skills? The skills are divided into three general categories – Crafting Skills, Gathering Skills, and Mission Skills.

• Gathering Skills - Pretty much exactly what they sound like. Gathering skills are used to gather materials for crafting skills, and they can be used on associated gatherable items in the world as well as sending your companion on gathering missions. Each gathering skill provides raw materials for one to three crafts; Slicing is the odd duck.
  • Archaeology studies crystal formations and archaeological finds. The crystals are used by Artifice to build lightsaber modifications and Force-user items; the archaeology fragments are used by Artifice and Synthweaving.
  • Bioanalysis is the art of collecting genetic material from creatures and vegetation, usually wildlife that you’ve defeated in combat. This includes cell fibers, bacterial strains, toxins, and medicinal fluids. These items are used solely by Biochem.
  • Scavenging is the practice of taking apart robots, among other things. Scavengers can pick apart defeated robotic enemies, abandoned cargo, piles of junk, broken-down vehicles, and more. Scavenging parts are used by Armormech, Armstech, and Cybertech.
  • Slicing is the last of the gathering skills. Slicing is Star Wars speak for hacking, and that’s basically what you do – you slice electronic safes, data terminals, mainframes, and locked footlockers. Slicing has a very varied set of rewards – it can yield credits (sometimes quite a few), rare schematics for Cybertech gadgets, vehicle and space upgrades for the space combat minigame, and mission discovery objects that unlock challenging missions for great rewards. Additionally, sending your companions on slicing missions can return augments for craftable items, or items potentially related to any crafting skill!
• Crafting Skills - also fairly self-explanatory. Crafting skills make stuff out of the things you get from gathering and mission skills. The most important thing to note is that while any number of your Crew Skills can be gathering or mission skills, you may only have one crafting skill per character. Another thing that may take getting used to if you’re used to other games’ crafting systems is that a lot of the time, most of what you’re going to be crafting are actually either unaugmented items, or item augments. The item augmentation system can be touched on at another time, but basically what it amounts to is this – if you build a set of armor using Armormech, you might actually build an item with four empty augmentation slots – but then you can fill those augmentation slots with other items built by Armormech to create a piece of armor uniquely suited to your class or role.
  • Armstech is the fine art of building guns. It’s weaponsmithing for the tech users – Troopers, Bounty Hunters, Smugglers, and Imperial Agents. If it goes ‘pew pew,’ an Armstech can build it. Armstech uses the metal gathered from Scavenging, as well as prototype schematics and compounds from Investigation.
  • Armormech is the armor counterpart to Armstech – it builds armor for tech users. It uses the same materials, too – metals from Scavenging and random goodies from Investigation Underworld Metals from Underworld Trading.
  • Artifice is used to create Force-user wieldable dealies, such as lightsabers and lightsaber enhancements, color crystals, generators, and Force focii. They can also create color cartridges for non-lightsaber weapons, such as blasters, according to their codex entry. You’ll see an absolute ton of Force-users take this so they can try to get a differently-colored lightsaber crystal, I guarantee it. Artifice uses the power crystals, color crystals, and fragments from Archaeology, as well as the gemstones from Treasure Hunting.
  • Biochem keeps you healthy and on the good drugs. No, really! Biochem creates both temporary use items (such as health-restore medpacs and stat-buffing stimulants), as well as creating items for the Implant equipment slot for basically any class or role. Biochem uses the biochemical samples from Bioanalysis, as well as the medical supplies returned by Diplomacy.
  • Cybertech builds an odd collection of goodies – droid armor (for your droid companions), earpieces (for you), grenades, armor, armor mods, and miscellaneous gadgets. They create the items you’ll be popping into your Earpiece equipment slot. Cybertech crafting is fueled by the scavenged metals from Scavenging, as well as the rare illicit metals gathered from Underworld Trading.
  • Synthweaving is the Force-user equivalent of Armormech, to put it simply. Synthweavers create items that the Force-sensitive classes can wear, created using the crystals and fragments from Archaeology and the luxury fabrics and underworld metals provided by Underworld Trading.
• Mission Skills can be viewed as the “high risk, high reward” category. Mission Skills have absolutely no gatherable nodes – essentially they consist entirely of missions, and given the broad range of possible rewards for each, you’re rolling the dice as to whether you’ll get something you need or not. However, each one has its appeal, and the rewards from Mission Skills tend to be kind of nice, even if they’re not quite what you wanted – you can always go pop them on the Galactic Trade Market, after all.
• Diplomacy is for those who truly want to max out their Light Side or Dark Side morality, even moreso than what quests will allow you to do. Diplomatic missions are all clearly marked as Light Side or Dark Side aligned if they can shift your morality, and sending your companions on these missions can yield morality points, medical materials for use in the Biochem craft, medpacs, stims, adrenals, and companion gifts. (The last one is a common thread of all the Mission Skills – they’re a constant source of companion gifts to raise companion affection.)
• Investigation turns you into, well, an investigator. Your companion will be out researching, gathering, analyzing, and decoding secret information. You can receive various items involved with Armstech such as rare compounds or weapon parts, prototype schematics for any craft, or companion gifts.
• Treasure Hunting is pretty much exactly what it sounds like. Your companion hunts down caches of treasure, returning with rare gemstones used for the prototype and artiact schematics in Artifice, lockboxes containing items or credits, and companion gifts.
• Underworld Trading is the shadiest of the Mission Skills, but don’t worry, it won’t affect your reputation – or your morality. Underworld Trading deals with the galactic black market, and can yield luxury fabrics (for Synthweaving), underworld metals (for Synthweaving, Cybertech, and Armormech), space upgrades for the space combat minigame, and weapon/armor modifications, as well as – say it with me – companion gifts!