If there are flaws in the appraisal that vary from industry standards, then the underwriters from your lender would reject it and require a new one to be done.

I did add a little when they uncovered some unplanned repairs (approximately $500 additional).  

@Eric DeVito   Your numbers are flawed somewhere. 

Although, it does not pay for slow repair work or repairs from an uncovered peril.Hope that sheds some light on it.

They don't uncover interests; build rapport; or anchor the purchase price.

If an actual foreclosure has not yet happened, then finding out the ownership of it usually is uncovered at the county tax office and where they are sending the bills.  

@Mark Nolan & @Jesse Stemle - I will make sure to check out the podcasts, blogs, etc...seems like there's a ton of hidden gems here just waiting to be uncovered!

A big problem with the 50% rule is that the largest expense of that 50% is cap expense which tying it to rent rather than size, bathrooms, quality of products, etc. is flawed. 

Having worked many of these deals of all shapes and sizes, I recommend you give the above points thought first so you can uncover how intensive of an investment you want this first deal to be.

The next two that I have started are Pitch Anything: An Innovative Method for Presenting, Persuading, and Winning the Deal Klaff, Oren and Making The Yield: Real Estate Hard Money Lending Uncovered Buscemi, Salvatore M.