Where can you find a map with house numbering?

Open Street Map gives house numbers for houses in many locations internationally. Although they don't have 100 percent coverage, they do cover most large cities in the USA.

Open Street Map is usefully Open Source, so you can add information about your local area if it isn't already covered.

Google Maps is working on a solution to getting house numbers onto their maps, but they aren't quite there yet. You can often use Street View to locate a specific house since house numbers are often visible from the street. Even if all of them are not, if you can see one house between house 100 and house 104, you may be able to see house 102.