If you are looking for technical staff, then you are better off using a niche job board.
I use both Monster and Dice. Dice is the proverbial niche site and yields *far* more quality resumes than the bigger boards.
Do not waste time or money posting Information Technology jobs or engineering positions on a general site.
After all these big, general sites are online sources where people hire secretaries and constructions workers. No offense.
Save time, post on Dice. By the way, PostOnce makes it easy.
Believe me I know, because I have tested this over many months.
Dice has an impeccable online pedigree and an excellent reputation as the best IT related jobsite on the Internet.
The name Dice comes from the acronym, "Data processing Independent Consultants Exchange". The term, "data processing" has not been used for years, but this is a testament to their longevity.
If you want to find engineers or IT people, start first with Dice. I find a lot of these types cluster around the San Francisco Bay Area Silicon Valley and Dice is very strong there.