Valuing Property

[Hal Cranmer]

I was wondering how investors are valuing property these days? I have a realtor send me listings of properties that I am looking to rehab, but I just don't have a great idea of what is a good deal or not - other than a small area of my city (Minneapolis) where I have rentals.

Does anyone have a good system to determine:
1. Finding areas that are appreciating or at least has homes that are selling.

2. Looking at comps to get a good idea of what would be a good deal? It seems like comps are all over the place these days.

3. A more 'scientific' approach to determining values? In other words - I get the networking with realtors in an area or looking at demographic information (which seems pretty scarce for good information) - but do you guys use spreadsheets or other programs to track properties sold, listed etc.?

Thanks for the help and my apologies if this has been discussed before in these forums.