Don't over improve. 

Unless you have the ability to access the property pre-foreclosure, you are effectively buying sight unseen at the auction.  

But non-lenders cannot reasonably get access to it short of bribing someone from within. 

Looks to be in good shape with some room for improvements.   

Great opportunity to improve terms ;-) 

Also, dont forget to add other costs to your depreciable basis of the house such as:1) if any improvements were done to the house2) The following items are some of the settlement fees or closing costs you can include in the basis of your property.

Our plan is to live in the stick built home that is there now, improve the lot add a Manufactured Home, rent it out, then rent the first home and move on to the next deal ASAP. 

Primarily I build custom furniture, as far as the home improvement side: general home repair (doors, drywall, paint etc).  

My question is, what kinds of things should I look to improve, and how do you stop yourself from going further?

I am looking at a building that I can't get access to until after I buy it at the tax sale.