There are two ways you can get this information.
First, perform a search on Trulia, select a home similar to yours and click on the Detail Page for the property. Scroll down and Trulia will have some information including graphs of market activity.
The second is to contact a local real estate professional and let them run comparable sales for your home. I suggest having agents from 3 different companies over. They will provide a range of information, usually with two in general agreement.
For price per sqft, this may/may not be an accurate indication of value for a property. Those homes within platted subs of same lot size would be more accurate than others. Calculating by sqft may not correctly value lower levels or differing lot sizes.
For real estate, most advertised sqft use above ground sqft. There are a few exceptions for bi-level, tri-level, quad-level homes were below grade sqft are included. Most MLS's allow a separate data point for below grade finished sqft.
If you look on this website, there is a link for construction types that would provide a bit more information.