OP - it sounds like you're referring to my arches/milkyway shot I posted a few weeks ago that was lit with a LED headlamp, correct?
http://www.thephotoforum.com/forum/landscape-cityscape/336364-night-delicate-arch.html
+1 for everything said so far. remember that the phase of the moon will play a big role, try to go on a new moon night that has clear skies if you can. there is some light pollution from nearby towns, but its nothing compared to where you're currently at...wide and fast glass will be your friend, if you're going to light paint, I'd strongly recommend a flash, or at least something that has a normal daylight color temperature, the light painting in my shot was completely accidental and the LED light source made the post production harder than it needed to be (that is if I had planned to light paint it with something with better color temp). the timing that has been mentioned is good, there are slight star trails in my shot when viewed at 100%, I shot ~65s, when I should have probably been closer to 45s give or take, and I was at 16mm f3.2 ISO 4000 on a D800e IIRC...that was using the 14-24 f2.8 lens....but even with your 18-55, if you're there on a clear night with no moon, you should be able to get some good shots, you'll also want a good sturdy tripod and head, and a remote shutter release, you'll likely be shooting longer than the 30s in camera longest shutter speed, so you'll be using bulb mode, and holding the shutter release down for the whole time of the exposure (or you can get a timer remote that will do that automatically, but they cost more)....practice getting a proper star exposure before you go if you can, even if you need to drive out of denver a little bit, its a bit different than a lot of other 'normal' types of shooting...
have you been to arches before? if you're going to hike to delicate arch for stars, and you haven't been there before, I STRONGLY suggest you hike up in the daylight, maybe just before dusk, it is easy to get lost as a lot of the 'trail' is on slick rock terrain and not clearly defined or marked (both my wife and I have been there several times before and we still got off the trail a few times in the dark), it might be wise to hike up at dusk, shoot/relax up there during the night, and hike back at dawn when you can see better. and bring water too, its not an extremely difficult hike, ~3mi from the parking lot to delicate arch itself, but its not somewhere you want to be without water in the dark...plus if you're there all night you can shoot the milky way in different positions, since it will move across the sky over the course of the night (or rather the earth will be the one to move)...FWIW I had cell phone coverage at the actual arch, but none along the hike to it.