good to go?

I'm about a week away from having my bp delivered and wanted to make sure everything was right, so let me run down what I have and you all can let me know if i've missed something or done something wrong. I've got a 20 gallon long aquarium, with towels covering three fourths of the top. I've got a ceramic heat emitter and undertank heater plugged into the reptitherm 500 thermostat with a basking spot of 90 degrees and the extreme opposite end of the tank at 80 degrees. Water dish, two hides, and digital thermometer/hygrometer. The humidity is a little funky, on the cool side its around 65-70 percent and on the hot side its 50 percent. I'm going to upgrade to a cage-by-design once the snake hits about 2 feet, but for now this is what i've got going. Let me know your thoughts. Thanks!

Wow, sounds good. It sounds like a better set-up than what I'm working on now, lol. The hot side is probably a bit drier due to the CHE. I think they dry it out a bit. Oh, and what are you using as substrate? I dont think you mentioned it. :)

as of right now just a single layer of newspaper as substrate.

Sounds pretty good, looks like you've done your research :P

I assume you're using a screen top? Just keep an eye on your BP's nose, to make sure he doesn't rub it.

Sounds like you are on the right track! Good job!
The only thing I can say is add some more newspaper.... three or four layers will absorb the "mess" a little better. It never fails... the snake always does it's duty while you are at work or school so you come home and you have a mess smeared all over the cage. :) The additional layers will also protect the snake even more from coming in contact with the glass directly about the UTH.

Definitely a very good start. I agree with Stormy that you should add a bit more newspaper, and if I were you, I'd try to move my water bowl into a different position to boost the humidity a bit on the warm side. Other than that, sounds great!

more newspaper; check. I am concerned about the hot side humidity, but i have the water dish covering about 10 percent of the uth and it just won't get it above fifty. I may have to wet the substrate a bit on that side as well.

Hats off for the prep work! Great to see you got everything lined up in advance.

I'd avoid wetting the substrate, particularly since you're using newspaper. It won't really help your humidity in that case. If you can experiment with your water dish, you'll probably find some way to reach the humidity you want with it. Some things you could do: use a bigger water dish, move more of it onto the UTH, or switch to a ceramic or glass dish (Pyrex pie dishes are <$3 at WalMart). Alternatively, you could just mist the sides of the enclosure each morning and that would probably create a big enough boost (but requires that you add that to your schedule).