Tim's photo gives the simplest description; look at it to start!
Most start and belay from the large left-facing dihedral at the bottom right corner of the Iraqi Wall; but Cottrell's guide shows the true line starting on the north side of the approach boulder instead, clipping a single bolt on it then scrambling up a low angle slab with pretty good friction, then stepping over the chimney to clip the fixed pin. This start is much easier than 5.7, but has only one bolt for protection.
The alternative dihedral start is cruxy and exposed 5.7 on river-polished rock off the ground, walking fingers through a crack on the left side, and occasional chimneying or stemming off the boulder opposite it. It has good clipping stances and bomber protection.
Once the approach boulder is passed, take a long hand traverse right under a small roof, using a finger crack and friction steps below, until a weakness opens in it. Don't let your rope slot in the right-facing crack just before the 5.7 roof ascent (or pull the roof earlier under a bolt for a 5.9 or harder way up). Friction climb the face above, moving left to a weak flake that should not be used for pro, past the flake into a right-facing dihedral with a protectable crack; then slab and ledge walking to the bolted Grand Central belay station (which is in clear sight from the flake/dihedral area).
The unstable flake can be avoided entirely by borrowing the 3 bolts from the Trout Fishing in America's second pitch, left around the loose flake to Grand Central. This alternate finish is around 5.8 right of the bolts or up to 5.11a left of the bolts.
A north-facing route at the central base of Gutenberger Wall, on the right edge of the Iraqi wall, and the left edge of the otter pool. From the approach trail, pass Buck's Bar and descend slabby ledges just below it; if you reach the Struggler Cliff you've gone too far.
The mental crux for many is crossing the Cosumnes on river-polished rocks! Don't mess with it when water is high; two memorials will remind you of how easy it is to die here in high water. Once spring melt is over, have at it, and enjoy a swim in the low calm otter pool on your way out.
Grand Central belay station at the top of the Easy Way Up is a pair of bolts with chains. You can just rap off with a 50 meter rope. Be careful pulling the free rope end after; the rope can easily get caught in rocks below in the current at normal or higher water levels.
Grand Central gives you access to every other climb on the Gutenberger Wall. Gutenberger Direct's pitch 2 continues straight from it. If you want to continue to the sport routes on the right side of the dome, follow a class 4 ledge system 100 feet or so, minding moss and anything loose, to the next anchor station - where you can start climbing Gutenberger Wall and Edge routes (instead of scrambling up the use trails on the far right).
Small trad pro (cams are well-suited) for the finger traverse. A couple of draws to clip bolts. Long slings to manage rope drag on this wandering line.