Wow, very nice!
Some notes before engaging in monster art:
1) The images aren't large. I believe they might average in the 150x150 range for a normal-sized monster, so expect to do a lot of resizing, we don't want itty bitty monsters nor normal monsters that take up the entire screen.
2) I believe we're still using RM2K3 (is that right?) so the monsters should be facing the right-side of the screen (for the side-view RPG battles). Regular monsters may engage in back attacks, which flips their sprite. Normal monsters should be a mirror image, but bosses or very large monsters can have non-symatry bodies.
I think that's about it.