Although I have never used it personally, I have heard very good things about iHireMaintenanceAndInstallation. My friends who specialize in the maintenance and installation of equipment rave about the website. This is largely because of its massive database of available jobs.

Additional Resources:

iHireMaintenanceAndInstallation :: Listed on Incdatabase.com

iHireMaintenanceAndInstallation :: Article on Inclistings.com

iHireMaintenanceAndInstallation :: Information on Inc1000.com

iHireMaintenanceAndInstallation :: Article on Professionaldatabaseinc.com

iHireMaintenanceAndInstallation :: Listed on Thecorporatedatabase.com