It was this time last year I decided I was going to do triathlon. I started running almost exactly a year ago. I started swimming in December. Starting now gives you lots of time to get in your training so you'll be ready for the triathlons in spring or summer.

As light_sabe_r said, look for sprint triathlons. The swim will generally be between 300-500m, with some being a pool swim. The ride will generally be between 10-12 miles. The run will generally be 2 miles or 5k (3.2 miles). You don't even need to run the whole thing.

Another convert! Cool!