potential 2nd deal

I just got off the phone with a person who listed his home on craigslist. They are wanting to sell there home because he got hurt and can not afford to keep making payment on the home. I asked the questions from Deans book, BARM and I beleve ther is a great oppertunity here to profit. he is currently 8 payment behind and the bank has sent him info on what he has to do in order to keep the home(pre forclosure) I think. The owner stated he looked around on the internet and thinks his home is worth $191k but say's he needs to sell fast and is asking $150k. I set a time to come and look at the house tomarrow 12/28. I know I will probably get an appraisal done(i think). Does anyone have any sugestions for me befor I go to the house, what I should look for, etc. I would love some good advice befor I go, it always helps to get advice from people who have been there done that. info on the home,
4 bed
1.5 bath
1224 sq ft
SFH, built in 1990
zillow showes the home zestimate of $191k.

thanks to anyone with advice.