Hello and Welcome to the board :D:D:D
Depending on the blocks, and the sizes of pieces in it, will really determine how big you want to go.
A 9 patch with 4" blocks would seem quite large finishing at 12". However a 12" finished block that has 16 pieces to it? those sized pieces may feel quite comfortable to you :D
Check out Blocks Galore on Quilters cache. There are many listed at the beginner level and different sizes too :D:D:D
http://www.quilterscache.com/QuiltBlocksGalore.html