Great article for total Tri newbies by Triathlon Magazine Canada on how to get started in the sport.
I'm a terrible swimmer, but it sounds like something I could even do with a little training.
http://triathlonmagazine.ca/racing/first-sprint-triathlon/
"These shorter races will typically consist of a 500 to 750 m swim, 20 to 25 km bike and a 3 to 6 km run. They are held by themselves or are staged in conjunction with the longer distance races. To encourage participation, many early season races will begin indoors with a pool swim.
The wonderful thing about a sprint distance is that anyone with minimal athletic background can complete it with four to six weeks of preparation, pro viding one can initially swim 50 m, ride a bike around the block, and walk a few 100 m."