here is what i would do with a brand new toon without alts
i would take slicing and two gathering skills if you plan to be out questing to level
one thing i did which really helped my state of mind was to vend almost all of the greens and blues i found
they rarely sell and need to be listed at such low margins that it is not worth the effort involved (especially with the poor gtn interface)
This is eactly right. As a starting new character, 'gathering' is the way to go. Bioanalysis, Scavenging, and Slicing. They're all basically 'free money' you pick up off the ground as you walk around. Once you begin to have more than one companion, you can keep the extras out doing slicing missions.
If you ever plan to craft yourself, keep those scavenged mats in the bank. Scav metals are good for several crafts. The bio mats are good for bio only.
Slicing missions and world boxes will sometimes return *other missions* which can be extremely valuable.
Also, 'Flashpoints' have some neat little tricks that make use of the various 'gather' skills.