EJ said it all right there.

my second favorite website!!!
Smooth on is the only way to go...
I started out the same as you... The very first thing I molded was a 140" whitetail rack... definatley not something a beginner should do and I would not recomend it in hindsight. I bit off much more than I expected to chew. It took me over a week, doing it right using smooth-on's products and methods shown on thier site. Came out fantastic! Also, they have some VERY detailed tutorials and even videos that will show you step by step everything you need to be sucessful.
Since then, I have made many other molds but... I have poured countless casts from that very first mold using thier products.
Fair warning.... once you do this you will be hooked

LJ