What sets are legal in Standard and Expanded?
Standard
Expanded
Additional expansions become legal the third Friday after they are released in the United States.
What cards got a reprint and are legal in Standard?
http://pokegym.net/forums/view.php?pg=stdformat
What cards got a reprint and are legal in Expanded?
Where can I find and print good proxies?
Pokemon Card Maker -Make your own for new sets, etc.
If making your own cards you can size card images to 3.45" by 2.48" in word and you can fit 8 cards to a page with landscape orientation and narrow margins.