On a more mundane note, on my last trip (Easter 2001) I saw a significant amount of rockfall, including one incident where a block the size of a large book fell 25m and glanced off the cliff 1m above someone's unprotected head (thankfully missing them in the process). I'm not sure a helmet would have saved him if the rock had hit, but having seen half a dozen separate rockfalls all on the one day, I would strongly recommend you wear one.
Also note that a new tourist track has been built that circles round the back of the mountain, avoiding the Giant's Staircase. Don't do what we did and blindly follow it, or you'll end up doing an hour's circuit of the crag! The correct turn off is about 5 minutes from the car, and is the only obvious track heading off to the left (it was closed off with a pile of branches when we were there). On my last visit to the crag, the turn off had been signposted with a little yellow sign saying "Climber's Access" and pointing to the left.
Pitch 1 24m 16M1 (23 free)
Pleasant enough moves up the initial wall, and then strenuous aiding up the thin crack through the bulge.
Pitch 2 22m 17
A great pitch with great exposure. The start is the crux, and although quite intimidating it's actually not too hard. Ask your belayer to watch carefully as you do the move, since if you fall off you could end up with a belayer enema! Continue up the airy arete to a belay stance (manky BB and good cams down low).
Pitch 3 25m 19M1 (19 when dry)
Probably a great pitch when dry, but it's strenuous and scary when wet. From the belay move left 3m, then follow the crack / corner systems that are bristling with pitons (they make great footholds in the wet!).
Pitch 4 20m 13
An airy step right leads to an easy, juggy face. Take care up this bit, since there's quite a bit of loose rock. At the top, step left to the big tree and a rap ring + FH belay / rap station.
Two raps (40m and 20m) lead back to the ground.
Pitch 1 (original first 2 pitches) 46m 17
A bit of a thrutchy start (don't carry a pack!), but lovely sustained climbing (crux) up the higher corner. Belay to the left below the flake if you can (keep a #1 friend for the belay).
Pitch 2 22m 16/17
A surprisingly cruisy pitch with just one or two balancy moves up the initial flake, and a one move crux to get established in the corner. Take care on this move - gear is tricky to organise and there's some big blocks perched precariously on the ledge at the base of the corner. From that move up the climbing eases right off. Belay on the ledge to the left (a big cam is useful here).
Pitch 3 25m 17
The pitch of the route, with a bit of exposure kicking in and some lovely slab moves at about half height (take care with gear). The final pitch is shared with a number of nearby climbs, so there can be a bit of a crowd at this belay.
Pitch 4 22m 14
A cruisy but pleasant pitch up a rounded groove in the headwall that takes some lovely wires. The final move before the top-out mantle is quite groovy if you avoid the ledge to the right. Placements for the belay are back from the edge a bit.
Walk left (facing the cliff) for about 150m and descend down the Giant's Staircase (quite obvious from the top).