I would start by checking out http://www.taxidermy.net/forums. Search the achives and ask questions. If you're talking about a shoulder mount, it may be just a little more complex than you think. I've seen kits that sell for around 50 bucks and you will have a mounted whitetail, but the quality may not be quite what you're hoping for.

I'm attempting to get into taxidermy as a hobby myself this fall. I bought several books & videos last winter and have gone over them several times. I also started purchasing some of the tools, chemicals etc. that I needed a little at a time. So far I've invested about $300 and I've purchased about half of what I need, excluding the specific form & eyes I will need for my deer.

I have 2 deer and a few other critters in the freezer. I should have everything I need to get started shortly after Christmas. Feel free to drop me an email & I will try to help with any other questions. However, you're probably better off getting advice from the folks over at taxidermy.net.