<p>Any recommendations for a javascript form validation library. I could try and roll my own (but I'm not very good at javascript). Needs to support checking for required fields, and preferably regexp validation of fields.</p>

I've used
this library
for a couple of personal projects. It's pretty good, though I have had to make my own modifications to it a couple of times - nothing major, though, and it's easy enough to do so.
I'm sure you already do this, but also validate all of your information on the server-side, as well. Client-side-only validation is rarely, if ever, a good idea.