It’s becoming increasingly possible to find out more about what your building—even your apartment—was like in a time long passed.

There are plenty of great ways to find out about the city’s best addresses; this recent Gothamist post introduced some ways to find out the history of your apartment (or one you’re interested in), your building, your block, and your street. This information has only recently been digitally catalogued in a way that makes it easy to search and cross-reference. In addition to discovering brilliant photography that brings the city of the past to life, historic photos of the city can provide a peek at your street long before you lived on it.

The New York Public Library’s Milstein Division of United States History, Local History and Genealogy has undertaken the project of helping solve the mystery of what your apartment looked like back in the day and possibly even a little about the people who lived there. This guide to researching locations in the city lists key steps you can take. Though serious sleuthing might require a bit of research (like digging into census data) the digital gallery is a good place to start. For example, you can enter your adress—or your street—here. Also included in the library’s research guide are resources like the NYCityMap project that can help you discover when your building was built, whether or not it is landmarked, who got the permits and did the construction and more.

There’s even a monthly class titled “Block and Lot: New York City,” that will teach you how to research New York City building history. With plans to expand in 2012, the class includes materials pertaining to the people associated with buildings. The Municipal Art Society of New York offers an annual four-week evening class titled “Researching the History of Buildings in New York.” The Brooklyn Historical Society also offers workshops on researching building history.