While real estate web sites give the most important information about homes to potential buyers, there are many other free web sites that give public information about homes in Minnesota. I use these sites on a regular basis, especially when I'm inspecting a flipped house. Not only is it interesting to see if permits have been pulled for work being done, but it's also interesting to see if the work has ever been inspected and approved.
Online Permits
I think it's wise to check the permit history when buying a home. The standard Seller's Property Disclosure Statement asks the seller if appropriate permits were pulled for any work performed at the property, but I think this is a fairly worthless question, and I often find the check boxes on this form just left blank.

If permits were pulled, it means the seller was given permission to perform work. It doesn't mean the work was completed, inspected, or approved. If you were buying a home, wouldn't you want to know if there were a bunch of open permits? Or that the basement was completely finished without permits? Or that no permits were pulled for a bunch of hack wiring that was done as part of a kitchen remodel?
The old timey way to check permit history was to call the building inspections department, but today there are at least eighteen cities in the Twin Cities metro area that give building permit history online. If I missed any, please let me know and I'll add them. I also have these cities listed under the "External Links" page on our web site.
*Minneapolis and several other communities use state electrical inspectors, so electrical permits must be looked up here: https://secure.doli.state.mn.us/etrakit2/AdvPermitSearch.aspx
Truth In Sale of Housing Evaluations
Currently, only Minneapolis and Saint Paul have TISH evaluations publicly available online. Here's how to look them up.
Minneapolis: Go to the Minneapolis Development Review site to look up information about properties within the city. Just type in the house number and street name; don't bother with things like "Avenue" or "East." If there are multiple listings for your search terms, you'll be given a choice. Once you've found the property, click "View this Property".
The next page will have a bunch of links at the top left, including one that says "Truth in Sale of Housing". Click this link to look up any current TISH evaluations. If there are open repair orders, those will also be listed here.