If all you need are photos, rather than scaled photos suitable for mapping, the Google Earth and the other free sources are you best bet BUT,
If you need accurate maps, then Fattdad's suggestion is "best", but also most expensive. It also requires field survey work, preferably pre-marking, for really reliable mapping.
If you local jurisdiction(s) have a good Geographic Information System (GIS) that may be adequate and probably least expensive.
For historical photos and "oblique" photos you may find these at your local library or University.
For simpler maps, suitable for preliminary work in the U.S., the National Geographic Society publishes Quadrangle maps on CD for reasonable cost.
good luck