Convert CPs to ships, vehicles, droids etc. Once you get a ship, you could also do small transportation jobs, but the credit market isn't too lucrative unless you have the larger ships to haul and the reputation that shows you can be trustworthy. But by buying and selling more and more goods, after converting CP entities to credits by buying/selling you can make credits then possible get facilities to bring in a stable income. But other than that, factions are pretty straight forward in earning a consistent wage.
Coveted items? Anything rare, i.e. Royal Guard Armor Sets, Lightsabers, ummm.... there's others too. Just whatever people feel like owning really, but there are many rare things that many would want but may be out of their price range.
Slang, not much more acronyms though:
WTB: Willing to Buy
WTS: Willing to Sell
FS: For Sale
FA: For Auction
Pretty simple, if you run across them just ask that person. There are also many acronyms used to describe ships.
Just to help a little further in acronyms, or slang, here's a list of ones I've seen. More or less of course.
FS-Force Sensitive/For Sale (Really mostly depends on where it is being posted, will obviously be taken as "For Sale" in Auction House and Trading Lounge.)
OOC-Out of Character (Mostly used to distinguish between the two forms of character in RPs, although has other uses.)
IC-In Character (Same comment as above.)
WTS-Willing to Sell
WTB-Willing to Buy
WTH-Willing/Want to Hire
TBA-To be Announced (Like RP start dates or auction end dates, that sort of stuff.)
I'm not too sure the difference between a DM and a PM. As I understand it, DMs are messages sent using the Message Network, while PMs are through e-mail. I'm sure someone will answer that here as well, and I'm curious to see if my assumption is correct.