If free job postings is what you are looking for, here's a list of online job boards that you may want to look at.
Some are totally free and others have a limit on the number of postings.
Preferredjobs.com (Employer services -> free basic posting 2 free posts)
DevBistro.com (Niche board for IT professionals)
GoFreelance.com (Finding freelancers who usually work projects at home.)
In addition to this, your local employment development department likely offers a posting service as well.
Of course the upside to free postings is well they are free. You can find good talented people in them. The downside is sometimes you get what you pay for. That means there is often a lot of old information. Phone numbers don't work, email addresses don't work. Outdated resumes. You see it all but if you are a quick at reviewing resumes you should be able to scan quickly and sort the wheat from the chaff.
If you get really fortunate, sometimes there are job developers who work for the state to help those looking for work find a job. They often have insight into who is a good candidate and really wants to work versus those who is just going through the process.
Finding that candidate who goes the extra mile and impresses one of these job coordinators could be gold. If you develop a relationship you might even get a heads up on some of the better candidates who come in while their search is just beginning.
Often times, those job coordinators are evaluated based on the number of people they help find work and stay in the workforce. A good relationship that works for both parties is something that has great value so find these people and find the ones who want to place good people. You will have a leg up on your competitors.
Finally, if you find that any of these do not include a free option, please let me know so we can remove them from the listing. Thank you.