I think Torhead needs to post an authoritative Crew Skills matrix. The others I find out on the Internet have either false or misleading information, or don't show the whole story. Most people I talk to in the game do not know what skill crafts which items. I have also heard in game and on forums that people abandon a skill after they found out more about it after training it. Why not understand it all from the beginning so you can make a wise choice?
See link below:
This was created in PPT so it doesn't look very nice but if you like the idea I can make a better looking version. It would also need fact verification, especially on the boxes on the right side (do all Gathering Skills allow for shortcuts in Flashpoints?) (do all Mission Skills give rare schematic drops?).