I highly recommend the landscape pages from the Road and Recreation Atlas by Benchmark Maps, available for various western states. These are better than the Delorme maps. I cut these maps out and trim the margins so they will fit neatly into a 12"x12" Aloksak, after folding in half. I've used these maps for tours of the Mojave area and the Nevada backcountry, in conjunction with the maps loaded on my Nokia N8 smartphone and a Garmin Foretrex 301 GPS, which gives location only (no maps). Neither the Benchmark nor Nokia maps show all the dirt roads, and the ones they do show are often wrong, but using all these tools together is enough to get me around. Mind you, I only need good maps and GPS location when I'm on dirt roads. If I was sticking to paved roads, just about any map would suffice.

I would be hesitant to use electronic maps only, due to possibility of the gizmo breaking in the field. At a minimum, I would want a paper road map at 1:1,000,000 scale or better. A small scale map like that is also very nice for getting an overview of the area.