WordPress Jobs is the only job board powered by WordPress itself. It operates similarly to WPHired: you fill out a form specifying what exactly the candidate will be doing, if the job is full-time or part-time, your rates and if you are open to negotiating, and whether or not you have a location preference for the developer.
You can ask for candidates to apply via email, online application, or by the phone and your job posting will be displayed for 21 days. The site is updated daily and has a huge audience of WordPress experts. We also recommend joining some of the WordPress forums and mailing lists to find out which developers are very active in the community.