Nataliya,
Homes that are in foreclosure in Nassau county can be found on foreclosure.com you can get a free month to search. I have found that the information is not always accurate and you will have to do more research, This is common of a lot of these sites though. I have paid service with many of them. Nassau homes that are found in these sites are usually of the low end. Most of the better quality foreclosures are purchased from lis pends and by agents, brokers or attorneys. Right now however there is a lot of bigger homes coming to this market and if you are working with a knowledgable agent you could get in early as the banks do not want these to be on their books.
The agent should be aware of lis pends and be able to help you through the process of acqusition. You will need pre approval, good credit and money down, an attorney that is fast to respond and knows the process and alot more time to do your own due diligence with town codes, taxes etc.. There is a lot to be aware of, but your reward could be worth the trouble and time invested. Be careful and I would advise a knowledgeable agent to help it is a asset not an obligation.
Nunzio 516 383 0700

REALTYTRAC.COM (DO MAP SEARCH FOR FREE)

If you're looking for bank owned properties, Anna is right - work with an agent who can help you coordinate the purchase of REO (Real Estate Owned) with the bank.

If you're looking for pre-foreclosures, however, where you can work directly with the homeowner BEFORE the property is so far down the foreclosure process, then you'll want to work with a local foreclosure data provider.

If you can't find a good local provider, your county court records should have pre-foreclosures, or 'Lis Pendens' which can help you find properties just starting the foreclosure process.

You may want to check MLSLI.com, and yes working with a Realtor will make your search much easier.

Anna