What maps do you use to find Water sources and Camp sites on trails other than the AT?

USGS 7.5 minute or the equivalent. Not 100% accurate, but usually helpful. Sometimes, though, you need to "pound the ground" looking.

there are a number of map options available, depending on the area you are planning to hike. National Geographic has larger scale maps of many of the national parks, and in the Sierra, Tom Harrison also has a good set of maps.

The more detailed and large scale topographical maps are best for discovering water sources. Guide books are often helpful, too.

The USGS quadrangles usually show both springs and seasonal creeks. But few of these have been updated since 1960 or so and you should understand that water sources can change over time or dry up due to current local conditions, so the only 100% reliable sources shown on maps are the larger watercourses or deeper lakes, which change very slowly and can withstand droughts. Of course, when you are on the spot, any water you find in front of you is worth considering, whether it is on a map or not.

Here in Arizona, there are a lot of springs marked on USGS maps. If you plan on hiking in Arizona or other parts of the desert SW, be advised that these are not all reliable sources of water. Some of the mapped springs have water only a few weeks per year while others provide water year around. Always check locally before planning a trip based on mapped water sources, at least in the desert.

caltopo

If you are exploring a new area, just carry enough water to get back to the previous water source. Then all you have to do is find a trail that looks fun and go hike.

Sometimes it means turning a planned overnight trip into a day hike, but that doesn't happen often around here.