Ridge of the caps
Last August I went up to the summit of Jefferson via the Ridge of the Caps trail. It is the shortest way to get up to Jefferson and the shortest way I can see to get up to the Presidential Ridge, excepting to take the cog rail or a car up.
This trail starts at a remote trailhead off of an unpaved road. We were able to drive it in a small car, but it can be a little rough in places. You start off in a boral forest, but soon, maybe 3/4 of a mile you will reach some large boulders on the right with your first great views of what lies ahead. Shortly after this you will intersect another trail. If you continue up the Caps Trail, you will find yourself above treeline, climbing somewhat steeply, over or along the "caps" (which we call "cobbles" in the Adirondacks). These are rocky outcroppings. You will find the trail marked by cairns topped with chunks of white quartz that caughes the sun's light and appears very bright.
There is no water to be counted on, not in the summer at least. I did find some water near the beginning of the trail, just at the "wet place in the trail, where a bog bridge has been built to facilitate crossing this spot. I went off trail to the right and filtered water from a hole in the ground. Otherwise, bring lots of water!
I really enjoyed this trail- but then I haven't seen any trails in the State of New Hampshire that I haven't liked. The amount of work needed to improve and maintain these trails is tremedous- I know, I did trail work myself.
Happy Trails!