One interjection to the response below: "large brand" brokerages in many cases still do not even have an adequate grip on buyer agency in NY (and should). Foreclosure info can be obtained at ANY broker- large or small- depending on their areas of expertise. Check with all of them. Opinion.
Foreclosure is an extremely involved legal issue and I suggest you tackle the subject starting with all you can get at the local library. Generally there is a before and after-foreclosure- process each side having various and abundant legal twists and turns. Of couse the final part is where the mortgagee or lein holder takes possession, commonly called the REO stage. Don't go into foreclosures blind but study the whole matter first. Then go to a large brand broker and they will direct you to the individual in their firm who is the specialist in the area. But be verbal and ask for the in-house expert.
Depp, because REO'S are new to many in NY, call around- find out what the activity level has been. I have to comment (having a listing that had a 515k contract denied by the bank in a short-sale situation) that REO'S can be a really good opportunity- the same house was listed/sold as a bank owned (yes, as we warned the bank, it did foreclose) for $405k. Most banks (hopefully) aren't that stupid, but as long as some are, the deals can be found. Good luck!