Newbies check list for starting out! Help!!

Starting off in the Sub-2 area just wanted to run a check list by everyone and see what you think!! Attorny - Check Title Company - Check Loan Servicing company - Check Mortgage broker - Check Buy and sell ads ready to list - check (farming neighbor hoods for FSBO's)-check All R/E forms have been verified for state use - check I have already started calling and talking to house owners and feel really good with this already (salesman by trade) so is there anything that I have left out that could possibly get me in trouble on my first deal? Also should I get a business licence, DBA or Corporation papers going before my first purchase or after? Any help would be appreciated. Steve