Founder Seattle Angel Conference, Lean Startup Seattle co-organizer,Startup Weekend Global Facilitator, Entrepreneur, Open Coffee connector, mentor, and freelance economic developer enhancing the startup ecosystem.
As people are suggesting, you should do good due diligence. This would talk a long time to answer well. Finding others who have invested before and getting perspective can be helpful. One place to start besides local startup groups is the book by David Rose called "Angel Investing"
it outlines some of the process of due diligence at an early stage Startup