Warning: this is a very self-serving answer so, beware.
When we were building Stack Overflow Careers CV entry we looked at all the web forms out there and tried to synthesize the best parts of each. I was surprised how few good web form examples there really were.
I feel our team built what is, in my humble opinion, one of the best web form implementations I have ever seen.

I suggest you try it out, it does require an OpenID login (sorry) but it's totally free to start and play with, and you can make a free public CV with a vanity URL if you want to.
http://careers.stackoverflow.com/users/login?returnurl=/cv
Example: we save via AJAX after every field is left, so you can leave the form at any time and not lose anything. But there are lots of other little details I felt we got right, so I encourage you to try it out and see what you think of our forms implementation.
Caveat: we did not do any of the jobs listing side, only the careers / CV specific functionality! So I can't speak for any of the job listings forms.