Listen to Valygrl! The deserts you propose to ride during the HOTTEST time of the year--with, as you say, no experience--is in my opinion courting misery at the best and disaster at the worst. I've toured through Death Valley many times but always in mid-winter or early spring. At that time (or late, late fall), the place can be dreamy beautiful. Keep in mind, during the summer in DV, daytime highs are frequently in the 115 to 120 deg. F. range. It is, literally, the hottest place on earth. Oh, but you can ride at night? The lows in the summer are usually in the 90's. And there are monster climbs to get in and out of there. As an added bonus, as you head into AZ, the conditions don't get much better.
Crossing NV along Hwy 50 is more reasonable but still pretty dang hot, but, being higher and further north, good riding can be had early and late in the day. You'll still suffer plenty, but your odds of surviving are high so long as you plan accordingly: Lots o' water, laying low during the heat of the day, etc. It's one thing to romanticize about the rigors of the road while sitting in front of a computer, something else entirely to feel your skin burn and the heat waves rising up off of pavement that is close to 200 deg. F. Plan on riding that country in mid-late Nov./early December, and you'll have a blast.
When I was close to finishing a cross country ride a few years ago, I spent the night in Needles. This was the first week of Nov. The next day, I had temps in the low 80's--pretty nice. Do some weather history searches by month for the different areas you are interested in riding and plan accordingly. Freaky weather can always hit--like the time we were riding Death Valley in early Jan. and temps climbed into the low 80's!--so be ready for the unexpected.
Planning, planning, and more planning.
Best of luck on your tour!