Contractor questions???

[Michael Moore]

I have a question about structuring an agreement with a general contractor. I am just starting out as an investor/rehabber in Columbus Ohio with major uncertainties on how to set up my relationship with my contractor. Should the contractors profit be included within his original estimate or should it come out of a percentage of the net? Do most investors insist on getting contractor's estimates in writing? Are material costs figured into contractors estimates or is that just labor? Could use some help here. Thanks.