Finally ready to buy an apartment? No matter how honest your broker is or how thorough your closing attorney, you’re going to want to do as much homework as you can on the neighborhoods and properties you’re interested in.
Here are some websites that will help narrow down your search and potentially uncover facts that may help you negotiate a deal and/or avoid nasty surprises (plus the cost of fixing them).
- StreetEasy.com  is the first stop for anyone and everyone in the market. This site will give you the lowdown on past sales and previous rents, as well as amenities, when you search the listings, but for the real dirt, check out StreetEasy Talk . Search by address or building name, as commenters may have already aired grievances about issues in the building. Nothing so far? Start a thread yourself to see what other people have to say.
- Of course, you’re also going to want to check the crime stats of any neighborhood you’ll be calling home. And the NYPD has all those crime stats online . Just download the PDF for the local precinct. If you don’t know the number, enter your prospective address into the precinct map . 
- Citymaps.com  lets you know exactly what’s in your potential new neighborhood from the street level. See every shop, library, and lot in the area within your search parameters. As one recent user says: “I just used it to find out where the nearest parking lots, coffee shops, and dry cleaners are to my new apartment! Rock on.”
- Particularly when it comes to new construction, you may want to peek at the offering plan (among other things, honing in on the special risks section ) before things get too serious. Offeringplanet.com  has scanned and uploaded hundreds of these documents, all or part of which can be printed by users. (TitleVest has more downloadable plans for $150 for a hard copy.) Offering plans can be tricky to decipher; you may want to enlist your real estate lawyer's help.
- Neighborhood blogs are one of the best ways to see the area from behind your computer screen. All the hyper-local news you can use, like restaurant openings, community board meetings, and missing pet notices, find their way to these online outlets, so Google around. Here's a sampling of our favorites; for more, check out CurbedNY , which aggregates a fair amount of news from local blogs.
- Upper West Side: West Side Rag. 
- East Village: EVGrieve .
- Lower East Side: BoweryBoogie , TheLoDownNY  
- West Village: VillageConfidential .
- Harlem: HarlemBespoke .
- Brooklyn: Brownstoner , FuckedInParkSlope , Brooklyn Heights Blog , Brokelyn .
- Queens: SheepsheadBites