Pros
You get to help people who want to go back to work get started on that process. If you are looking for work, some of these institutions are very helpful and they'll make sure they go out of their way to find what is right for you. If you are in a pinch and need something now and don't care what it is, usually within a week you'll have something.
Cons
Some of these are pushed so hard that you are just a body to fill a need. They don't care if you have office experience and only want something in a 25 mile radius, they will put your name in the system and you'll be called for only factory jobs and open house hiring for other counties an hour away. If they tell you, we will find you work to get you started and if you're wanting something else, we can help you with that ... it's a lie. Once you are on a job site they cannot help you get another job unless you quit the first one they got you. You have to give them two weeks notice or else that's a strike against you. So if you want a job in an office but they put you in a factory, the office job will be long gone by the time you are able to take it.