I did Snake Dike last summer. The recommendation to check out SuperTopo is a good one - I ended up buying both their Tuolumne and Yosemite e-books (you buy; they send in pdf format), and they were more than worth the price.
As for beta - the approach walk is long, but absolutely beautiful - think several hours minimum and possibly a good deal more, depending on how fast and efficient you are. Walk in and stay in one of the closer campgrounds the night before to cut it a bit, or start EARLY. (Of course, I can't advocate an illegal bivy at the base, but there are some spots up there.)
The first two pitches are a bit spooky - 5.7 friction with not the best pro (the first placement under the overhang on pitch one takes either the green or yellow alien, if I remember correctly - maybe bracket them with the blue and red when you put your rack together, to be sure). Then you're on a 5.4 staircase that runs up through an ocean of granite slab.
It's a dike full of knobs and chicken heads running in a curve up the wall. Awesome. From a gear perspective, the dike itself is seriously runout (like - leave the anchor, climb 70 feet, clip a bolt, climb to the next anchor), but it's dead easy. After the first two pitches, you won't need anything but a couple of draws for each pitch.
Our rack for the route was three small cams and four draws, plus four shoulder length spectra slings and a handfull of biners for building anchors at the bolts. (And I don't think we needed all the draws!)
The walk off is also pretty long (over the top of the Dome and down the cableway on the far side - fun!). The route and the walkoff get sun pretty much all day - bring plenty of water!
There are a couple of pictures (not so great) of the route on my pages from that trip:
www.tokyo_bill.homestead.com/yosemite2001.html
and
www.tokyo_bill.homestead.com/yosemite2001page2.html
and there are some more cool ones on the Super Topo site.
Overall, it's a lot of walking for the climbing payoff you get, but I'd do it again in a heartbeat!
Have a blast.
P.S. Okay GOclimb gave me advice on getting my page links to go live - let's see if it works.