Shit, there are dozens of great ways to cross Nevada and none of them are paved. A few board members and I drove from Salt Lake to the Monitor Range a few weeks ago and barely touched pavement.
In general, mountain ranges run north-south in the Range and Basin country. I recommend a good topo maps app (like
http://topomapsapp.com ) and scouting the various dirt roads that run east to west. Most either cross a pass or go through a canyon. You can't go wrong with either.
For camping, we usually just took dirt roads from the valley floor up to the cedar line so that we could cut firewood. It's not hard to find good camping at all.
Belmont, NV is cool to check out and good camping is nearby. Go on a Friday night when the saloon is open.
The canyons along the east side of the Deep Creek Range that straddles the UT/NV border have some of the best camping I've ever experienced.
Where are you coming from?