You have picked one of the best times to be in DV. Springtime with wildflowers I think is even better.
Off pavement capabilities as mentioned above open up many more option for rides. The North end has access to the Eureka Dunes and the Saline Valley Road along the Western boundary. Rough gravel and pumice routes lead to both. temperatures there are cooler in my experience than farther South in the park.
Some very good advice has already been posted. The AAA Death Valley map is very useful and free to members.