Good resources that are what Jennifer Lee was talking about.
Alleghany County Web Page that will tell you the current assessed value and appeal status, if any is in progress. It will also tell you the borough, if you weren't sure. There is also a lot of other misc good information. This is always my first stop when considering a property:
http://www2.county.allegheny.pa.us/RealEstate/Search.aspx
The county web page that details the millages for each school distrct, borough and the county itself. Click on the borough the property is in for all the detail. CRITICALLY IMPORTANT:
http://www.county.allegheny.pa.us/treasure/millmuni.asp
Most boroughs have web pages, and you should look there as well and call into them to get detail on utilities, ordinances, etc. The boroughs are often small enough that sometimes the person you talk to will know the property you're talking about and even the owner. I've talked to inspectors that told me all about how many times he's had to nag the owner to fix stuff, but they never did.
The utilities are all over the map in the Pittsburgh area, and they WILL kill you if you're not careful, especially on multifamily. Check them all: water, gas, electric, trash and recycling.
Good luck!