Originally Posted by visionology
Depends where your tri is. Pool is probably fine for distance training however I would get some training in, in the same conditions you will race in. When my sister did the Lake Winnie Tri the waves were so big it looked like the ocean, whereas in a smaller tri she did it was a much more calm lake.
This also includes bike and running. You don't want to road bike on just flat roads if the terrain is very hilly.
Perfect advice. If you give open water swimming a try you'll find that it's a totally different beast than lap swimming, even when comparing a very calm lake to a swimming pool. You can check out the forums at beginnertriathlete.com. They have region-specific boards and usually you'll find people who are looking for others to join them in an open water swim, a long saturday morning bike ride or a run.
As far as bikes go, I'll second the advice for checking craigslist. You really only need a decent road bike ($300 for a used bike would do the trick).