A) The search appears to be jQuery driven and just does a text search of the records that already appear on the page. This won't scale
B) I can't do a useful search: "Ruby developers with an hourly rate under $150 with over 2 years of experience"
C) You need standardization of the rate format to make it useful/searchable. Dollar per hour or something similar.
D) The technologies list is weird and kind of useless. I'm an expert in "friendster"? You either need a really comprehensive list of programming languages, technologies, APIs/Frameworks, etc... or you need an auto-suggesting free-input field basically like tags.
E) As other people have mentioned you can register with an e-mail of "a" and no password. Basic input validation is usually a given...
I'm not trying to knock your effort, but basically you're shoving all your DB records on a page, and using a jQuery plugin to search them. This might be a nice way to demo how jQuery works, but there's not much there, and you'll have usability and scaling issues very very soon.
You're also missing basic stuff like input validation, informative information, useful search, etc...
If you're just learning some web site design and development, then this is a great first site. However, it's not really a startup/web-app worth reviewing here at HN (imho). There's no business model, the functionality that exists is sparse and not really polished, there's nothing here that couldn't be replicated in an hour or two by someone else. The "find a coder" space is already served by a large number of sites that have a much more mature feature set and large existing user base. What is the new thing you're doing to compete?