I may be ready to start looking around for something new. Its been a long time since I changed jobs, and the last time I did it I answered a headhunter phone call and things just went from there. If I'm interested in talking with some headhunters, any tips for evaluating and choosing one? And is there any reason not to work with several at the same time (they have contracts with the companies seeking to fill positions -- not the potential candidates -- right)? My thought is to target specific jobs I want but to also find some search firm(s) who are out there looking for leads possibly before they are posted externally.

Finally, I assume that I should assume that anything I tell them (such as salary information) may be passed to the potential employers, and that I shouldn't tell them exactly what I make -- how much information would you give them to help them weed out jobs that are obvious no-gos?