I've been asked quite a bit for info regarding certain fishing spots that I've gone to.  I don't mind sharing that info at all, so don't take offense to this post. 

I made an effort starting last spring to survey (if that's the best word to describe it) the Sierras from Plumas county down to Yosemite.  I found some pretty good spots on the MFF, the East Carson, the West Walker and the MF Stanislaus.  I discovered alot of these areas by asking questions of fellow anglers, by driving all over the place, hiking all over the place and by reading books.  There are two I recommend as being really helpful in narrowing my search for good water and for marking them for historical reference. 

1).  Fly Fishing the Sierra Nevada by Bill Sunderland.  He covers virtually all the main waters from Redding to below Yosemite.  I've found some of his descriptions (especially of locations) a bit vague, but for a reference guide to particular waters and what to expect, it's a great one.

2).  Northern California Atlas and Gazetteer by DemLorme.  Great detail on small/dirt roads and camping areas.  If I find a prime location, I'll mark it in this book for reference. 

I also use a Garmin GPS whenever I hike an area I'm not familiar with and if it's any measurable distance.  If I find a good spot, I'll create a waypoint for future reference.  Really good investment. 

Can't wait for next spring when I can venture out again and find more spots.  Last year I only scratched the surface, but I have a better understanding of where to look now.