I'd check with one who knows your information (there is also a thread somewhere on BP where a CPA answers questions).

But they do not have the ROI that many expect, so check your numbers carefully....if you are doing this just for the $$ return you may be surprised.

Check out my personal favorite, Set For Life by Scott Trench , or The Total Money Makeover by Dave Ramsey.3.

I would also check references and make sure the installer is licensed and insured.Roofing has more variables-disappointments- than even plumbing and you want it done right the first time.

Check back soon for more adventures in investing.

Alex, check the forums for agents in Baltimore here.

Someone else had posted the same comment a long time ago, it would be worth checking it out to give you an idea.  

Go check those areas out back in the 90s.

And/or assume that everything is trashed and you have to rehab the entire house.I have bought houses without going inside, but you can usually get on the property and look in some windows. check the roof, exterior siding, main panel, etc and get a pretty good idea of what the house will need.

Check into their BBB rating and real reviews.