We put half the roof on this morning before the temperature reached 90 degrees. After that, we declared victory and retreated to the house to watch the Olympics. My daughter (age 16) cut shingles and fed me materials, so we did it in under two hours once we got going.
I decided to go with a ridge vent after all. I bought the Cobra Vent kit from Home Depot for $55. It's 20' in length and 8" wide. It looks like a very loose scrubbing pad material that allows a lot of air to flow from the ridge. I don't really need this in the shed - 3 or 4 roof vents would have worked fine, but I wanted to test it out. 4 roof vents cost about $40, so the cost is comparable.
I want to put this on the roof of the garage I'm going build, plus our house, so it's good to get a bit experience with it before I spend a whole lot of money. I can see how you could cut this into pieces and use it for venting in the eaves with little effort.
I bought a coil nailer a couple of years ago, when it was on super-sale at Harbor Freight for about $70. It shoots both roofing and siding nails - and it makes quick work of putting shingles down.
If you are going to do any significant amount of roofing or siding, I really encourage you to get one of these. You can rent one, or for about 3 days rental buy one at HF. If I were going to roof everyday (no thanks), I would go with Senco or some other industrial brand, but for the DIY person, it's hard to beat.