Hi,
casual cyclists should start by getting a trainer and a couple dvds from Spinervals.
I suggest the first one to be Sweating Buckets. After you try that, you will have a handle on what they are like and what their rating system means.

Nashbar has a fluid trainer that has a very nice rep, and it's almost always on sale. I use a Kurt Kinetics, but there are a lot of nice trainers out there now. Just pick the flavor that suits you.

If you are competitive, jump straight to the Kreitler rollers. If not, you can get rollers later.

You will want a cheap rug or pad underneath, a place near the TV, and a fan on a stand.