How do you know a contractor is a good one?

[Youdo Thirakul]

I'm trying to build a team, and of course I need a contractor.  My brother in-law referred me to one and he is cool but something he won't answer my text about meeting up or what he thinks about a house.  Is it because I'm new and he thinks I'm just wasting his time? Anyways I do want more then 1 contractor if I want to do this full time.  How are you guys finding contractors? Any warning signs? or anything I should ask or look for when looking for contractors?  Will a contractor help me if I just need him for stuff I don't know anything about? I ask because I do know how to do some of the job, like putting new floors, paint, etc. small stuff.  Will a contractor be offended if I told him I just need him for half of the rehab and the other half I can do ? Thanks guys