Real estate values have to be determined, and disclosed in your bankruptcy petition. You can use appraised values, but often times, the counties assessed value can be used. The Beacon website should list your real estate where you can get approximate values for your real estate.
In order to qualify for a chapter 7 bankruptcy, an individual or family, must be below the threshold amount of the "median" income. This varies from state to state and family size.
If your combined family income is above the median, then the next step is to determine whether or not you pass the "means test". In the "Means Test" link, enter your ZIP code, and scroll down the page and fill in the requested information to determine whether or not you pass the means test. If you do not, then a chapter 13 may be your only option.