I agree, get the setup ready ahead of time if you can. That way you can test out lamp heights, wattages, and enclosure temperatures. That's usually something that needs to be tweaked now and then anyway but it's good to have it tested out to begin with. If you run through your setup with us, we can check for potential problems and make suggestions as well.
I don't measure humidity but the humidity in my house is usually pretty low. As long as the air in the house doesn't feel sticky to you, it should be fine. I use a temperature gun to measure surface temps. I love the instant readings and portability it provides. A digital thermometer with a probe is also a good choice because you can put the probe on the basking surface to read temperatures accurately. They just take a half hour or so to get a good reading so they can't be moved around as easily between basking spot and cool side.
Def before. I had a couple of itms not work when my set up arrived, and the actual viv got broken in transit. And it took me longerr to get it all put together than I expected. So best to allow for delays. I also liked having a couple days to play with getting the temps right.