Main street runs right up the center of the photo....
Main Street Crack ends at a small tree/bush, then there is a short slabby section of rock below The Great Roof just under the summit. This is the giant roof you can see from the ground. Main Street (right) finishes in the corner at the right side of the roof. Main Street (left) continues straight up from the bush to an awkward stance under the roof, then traverses left (scary) with little or no protection to gain the prominent arete and then to the summit. In both instances, surmounting/bypassing the roof is the crux. It is possible, perhaps advisable, to set up a belay near the tree/bush so your belayer can see what's going on. if you belay from the ground, the leader will disappear under the roof and you won't see him for the crux moves.
Near the left side of the Main Wall about 30 to 40 feet to the left of the Library dihedral look for the long, left-leaning crack system that starts just to the right of the small buttress. (The other side of the buttress near the tree is Witches Brew.)
No fixed gear. Build an anchor on top--trees are too far back.
A great route. Starts just right of a small inside corner. The start is a bit runout, but pretty easy. I recommend doing it in one pitch. Some parties head right and end at the ledge, but going through the right end of the roof is the best part of the climb. I usually tie off a tree about 20 feet back with the rope and back it up with some gear right at the edge to bring up my second.