Bicycle Mechanics - Whats wrong with my bike? or is it me?

I have just purchased a Schwinn Super Sport ’01 with a Shimano Ultegra Triple. However I am having problems shifting, :( I can't switch gears. I'm not familiar with these types of gears, and was wondering if there is anyone could help.

t would help if you might describe what you are trying to do and what is not working. Did the dealer show you how to shift gears with STI type shifters?

Using the entire brake lever, while pedaling, pivot the entire beake lever toward the center of the bike to change gears in one direction. Use the little levers under the brake levers to shift in the opposite direction. The left one control the front chain ring derailleurs, the right one controls the rear cassette derailleurs. You need to pivot the brake levers quickly and sharply to shift properly. A quick twist the full amount of play and then a rapid release.

Gosh, this is really hard to describe, and I am assuming my Shimano 105's shift the same as the Ultegra, which I believe they do.

Someone else help me out here in describing this, or perhaps Sheldon Brown has a good description on his web site.

Go back to the bike shop which sold you the bike, and ask for a demo on how to shift gears.
You need to keep pedalling when you change, and never back-pedal. You use the two levers on the brake units to shift in different directions. Press the levers from the outside, and watch how the chain shifting mechanisms move.

Use the gears to keep pedalling at a quite fast rate. Smaller rings at the front are easier to pedal. Bigger rings at the back are easier. Make sure when you stop the bike that you are in an easy pedalling gear for starting again.