When do you want to go? Are you interested in the southern starting point or the northern? Are you wanting to climb anything while your up there?
I would recommend doing it N to S and plan on nearly a week. The record is slightly less then 24 hours I think.
You will need a wilderness permit and you will have to have a detailed plan of your camps; the snow is just coming off now with Cascade Pass being snow free, I spent last weekend on Sahale. If it hasn't been mentioned summitpost.org and wta.org are great resources, read Beckey's book. A basic mountaineering course is essential,plan on a standard mountaineering spread of gaiters, ice axe, crampons, rope, your preference for crevasse rescue and lightened pro, poles are helpful. This is not the place to try trail runners with aluminum crampons. The goats have been known to nibble salty pack straps left unattended.
The flies were bad down low.