Posted 21 March 2012 - 12:31 AM
First pick up some good books on mythology or reference books on mythological creatures.
2 that I'd recommend offhand are:
Giants, Monsters, & Dragons: An Encyclopedia of Folklore, Legend, & Myth, by Carol Rose.
Sprites, Faeries, Leprechauns, and Goblins: An Encyclopedia, by Carol Rose
If your looking for info on any specific creature from mythology just ask. I've got numerous books on folklore.
The book RPG Maker For Teens, by Michael Duggan has some info that you may find helpful in it. The book was written for VX and they have a site with some support files for it. He has a walk through on how to create a custom enemy in it, some drawing advice, and lots of info on creating monsters and enemies in it.
Software wise I use 3D software in conjunction with GIMP & Manga Studio EX. GIMP is free. You can get Manga Studio EX cheap at Amazon& Smith Micro put it on sale for 50% at various times during the year too. I avoid Adobe as they have bad tech support I've found in the past & they are making some changes to how software upgrades are done this year as well that makes me less likely to use there software.
You can make cell style images easily with some 3D software of creatures, people, etc. which is a huge thing if you can't draw and if you can draw that can you make a good picture very quickly and save lots of time. You do have to watch if any restrictions for usage of a 3d model exist though as some can be used only in personal projects, some for commercial & personal, some don't allow for the use in games, and some have usage options you can purchase.
I van put together a list of recommended 3d software items if you're interested in this route in a day or two,