Veronica - I would consider an Olympic distance - not too short on the bike or swim and enough distance on the run to push you a little (esp since your 3mile run time makes me jealous right now )

Oh, and for the transitions - the harder the swim, the longer T1 becomes for me. What can I say - if i'm already tired at that point, I just don't want to stress out at that moment But in general, the shorter the tri, the more important the transition. I can do T1 in under 2min, and T2 in 1min (assuming the transition area isn't too big) It can be the difference in placings. I would say, if you're just doing the tri for fun, don't stress out too much on them. If you're trying to place, definately practice them.