Our city politics mailing list is an excellent place for me to read about other people's experience with the candidates, sometimes going back for decades. I've found it a very useful tool in determining which candidates to support.

Also, I tend to support candidates who abide by the endorsement process (endorsements come from a variety of local conventions prior to the primary; I've been a delegate), and not those who do not abide by the endorsing process unless they are the endorsee.