Useful Links - some spoliers

Crafting Info

*NEW* http://www.swtor.com/community/showthread.php?t=45866

http://www.swtor-spy.com/crew-skills/ Tells you which crew skills work with each other.

http://www.swtor-life.com/crafting/reverse-engineering-swtors-ace-in-the-sleeve-for-crafting/4829/ Breakdown of Reverse engiring(sP)

http://www.swtor-life.com/crafting/swtor-crafting-crew-skill-combos-more/4861/ good breakdown and explanation of crafting.

Talnet Calc - (this is based off of the most recent beta patch and could change before launch, but its should give you a good idead of each Advance Classes options)
http://torguild.net/calculator/


Class Companions
http://www.swtorstrategies.com/2011/07/swtor-companions-list.html

Data Cron locations
http://www.swtorstrategies.com/2011/10/complete-datacron-location-list.html