All the jobs that i found over the years have been from me contact the employeer. However it does not hurt from time to time to have another set of eyes looking out for a job for you.
However dealing with them is the same way in which you will treat the meeting the employeer. You might be able to get away with being a little more relaxed with a recruiter. But at the same time, you mess up with them, you rarely get the a phone call back from again.
With all the jobs that I have applied for via a recruiter, I have never been called by the same recruiter for a second job. Same office or firm, but never the same recruiter.