You are definitely in the right place for your inquiry.
The first step is to find a starter set that has everything needed to get up and running. This is the easiest way to go. Lionel has many starter sets. http://www.lionel.com/Products/Finder/SearchResults.cfm?doAction=Browse&CategoryID=37 The LionChief sets are remote controlled, with many features. Set up the trains on a table, or even the floor to familiarize yourself with them and their operation. You can purchase more track http://www.lionel.com/Products/Finder/SearchResults.cfm?doAction=Browse&CategoryID=528 and accessories http://www.lionel.com/Products/Finder/SearchResults.cfm?doAction=Browse&CategoryID=39 to enhance and enlarge your layout.
Contact a contractor to discuss your desire to make a shelf layout along the walls. Show them the set to get basic dimensions of the track and leave extra width for trackside accessories if you want.
Once the shelf is built, lay the track, add the power, hook up the trains, and you are all set.

Larry