A useful article regarding contractors:
Its not too different for commercial construction either. Most Contractors are good, but there are some sketchy ones out there.
If I were to add to the list, I would add that you MUST make sure that you get FULL UNCONDITIONAL WAIVERS from every subcontractor that has worked on your project. Essentially, a waiver affirms that they have been paid in full and are waiving their right to put a lien on your property later.
Believe it or not, just because you paid your contractor doesn't mean that they will pay the subs (electrician, plumber, etc) that worked under them. A subcontractor and/or supplier have the right to place a lien on your property if they are not paid!
I have found that the most effective way is, at the final pay request, pay the sum of the subcontractor fees but withhold the General Contractor's fees. AFTER you receive all of the FULL UNCONDITIONAL WAIVERS, pay the GC.
Again, most are great but be careful...