For maps the old fashioned 24K or 100K Topo maps are about as good as anything. The BLM Rec maps are typically 100K, show ownership and aren't too bad for general navigation.
Yep! Back when I was first exploring SE-OR and NW-NV I bought all of the USGS and/or BLM 100k series of topo maps covering that area. (I'm a mapophile) They seem like the perfect scale for road-exploring 'cause you don't need as many (as the 24k) to cover a large area and you don't need the detail required for navigation by foot. BLM maps showing ownership are great so you don't end up dead-ended at a "No Trespassing" sign/gate after a long hard road. This has happened to me a couple of times when using the USGS version 'cause it didn't show that the route included large private tracts.
I think the lack of road-exploring guide-books or tour-guide-maps to the area is because little of it is recognized to be as spectacular as, say, SE Utah or the Sierras, for example. There are no National Parks or Monuments in SE OR or NW-NV, though Steens Mt has been mentioned as deserving of National Park-hood. Steens really is spectacular when you get high upon its west slope -- 4 major glacier-carved U-shaped valleys as well as an almost mile-high drop down the east face (
I've posted a lot of photos in the Steens Mt, Oregon Gallery)....though it doesn't look it from the western base. It's similar to how the Sierras don't look like much from the western foothills, but are spectacular on top or viewing from the eastern base -- so is Steens.
The suggestions for destinations that have been given are way too many to explore in a couple of weeks, of course...but you've got plenty to choose from.
What I like MOST about the area (and in general) are the big, naked, land-forms and lots of vertical contrast. Such as Hart Mt plunging down to the Warner Lakes Valley to west and Steens Mt plunging down to the Alvord Basin to the east. And then there's the extreme flat bareness of the Alvord Desert and the much bigger (but more-visited) Black Rock desert playas. In addition to their stark, other-worldly beauty, all kinds of wild stuff is possible on those enormous flat obstruction-free parking lots! I've ridden my bicycle in the pitch dark and even with my eyes closed for a couple of minutes -- absolutely unconstrained bicycle riding is very cool and rare to find. (foolhardy stunts with the truck involving blind night-driving and driverless driving are also possible, but won't be mentioned
)
I know Oregon natives who've only heard of Steens Mt and have never been there and who've never even heard of Hart Mountain or the Black Rock Desert -- Enjoy your exploration!