Welcome to the Clyde/Athena Forum.
This is a great place to get started. Some here have some truly inspirational stories.
Might I suggest reading the "New Embarrassed Rider" thread
http://www.bikeforums.net/showthread...arrassed-rider
And the sticky thread ... scroll down to the area on bike buying...lots of links to good info there:
http://www.bikeforums.net/showthread...tickies-linked
How long has it been since you rode a bike? What type of riding to you hope to do (road, dirt trails, multi-use paths, crushed rock trails etc).