Just know where your studs, any electrical, and plumbing are. I have cedar shake and put my vent through the side of the house, with about a seven foot run. No ladder work, and you just need the right hole saw and some paintable caulk for your dryer vent. If all you have is a straight shot through drywall, plaster lathe, insulation, and siding, this is a good way to go. There are maximum dryer vent lengths here: http://www.applianceaid.com/vent-length.html
You'll have to pull the roofing back (shingles, felt paper, etc.) if you go up, so you can install proper metal flashing, black felt roofing paper over that, and then redo your your roof shingles. I had to do that with a leaking pluming vent, and it was a lot more work than the dryer vent. I also used some roofing tar.