crymod.com is a good place to start. http://sdk.crymod.com/display/SDKDOC21/Home - this is a gold mine.
The official editor has not even been out for a day. Most of the tutorials for SB2 will get you pointed in the right direction. As far as mapping goes - SB3 is one of the easiest to use. It would really be good for you to learn Max and Maya - at some point you will need meshes that are not in the game. SB3 is like playing with a lego set - you just arrange cryteks pieces. Problem is, they are really big pieces.