If you are just starting out and want to create creatures, then this has to be one of the first tutorials to watch.
Though this is a mini tutorial, the information is very well presented. Shannon Shea goes through a bit of history of what was available in the past and what is available today. He walks you through all the oil based and water based clays on the market and how to make a warming oven to soften up the oil based clays so that you can do quick build ups of smaller character creations.
The one aspect of this tutorial that I felt was weak, a if an after thought was the epoxy clay. Shannon shows a product called ProPoxy. This is a fast set epoxy clay. He makes mention of what he calls a cousin of the epoxy called Magic Sculpt. I disagree with that statement. Quick set epoxy clays are cousins, Magic Sculpt is not quick set. You have a work time of around 45 minutes. Clean up is with water and water smooths the clay. I have used Magic Sculpt for the past 4 years now and it feels more like pottery clay than an epoxy clay. Epoxy clays can feel a bit rubbery and a lot of them tend to not want to form into the shape you want. Magic Sculpt can be drilled, sanded, carved, etc and it is very good keeping a hard edge to it after it has cured.
I have to run now, but I will make a follow on to this post with my thoughts on the wide range of epoxy putties out there that are not quick set.