Effective, timely, and appropriate follow-up is crucial. You must demonstrate initiative and being pro-active if you are going to be successful. It's inconsiderate and inappropriate. Learn to control those little idiosyncrasies that are distracting. It's usually inappropriate to ask about salary and benefits in this setting.
Some employers feel it is acceptable to ask it, others feel it is inappropriate.
All agree that if you feel you need to know more about this area, the best way to approach it is to ask for the recruiter's permission and guidance on the subject. There are no short cuts to success. I'm interested in and the employers were very nice about helping me out. I spent my time at the job fair talking to employers who may be able to hire me. This can be viewed at the OCaS library.