Choosing a recruiter is one of the most important aspects not only of a job search but also of long term career development. Here are a few guidelines I would suggest:

1. Check Reputation -- ask other professionals which recruiting firms they recommend, as well as which ones to avoid.
   
2. Experience. How many years have they been recruiting? What are examples of their client base (companies where they have made placements)? What is the length of time servicing that client base?
   
3. Do they specialize in your area? Generalist recruiters (recruiters who place a wide variety of different positions) don't typically have the quality of contacts or the level of knowledge to give you optimum service and results.
   
4. Ethical practices and approach! A recruiter should never ask you to falsify information on your resume or ask you to do anything unethical.
   
5. Will only send your resume out with your permission, after he/she has explained the opportunity to you.
   
6. Look for a recruiter who takes the time to understand your values as well as your personal and professional goals.
   
7. Never Pushy - No Pressure: You should never be pressured by your recruiter to make a particular decision. A good recruiter recognizes that you are an adult capable of making your own decisions. He or she may offer guidance and/or input, but ultimately he needs to respect your decisions.