Good info here about any issues with the park, roads, and camping. North Rim will be closed now. South Rim will be cold (sub freezing) overnight and pretty cool during the day. You'll have to decide when the weather will allow you to go?
Also there's a NOAA weather radio feed that gives real time conditions in audio format.
http://www.wrh.noaa.gov/fgz/WebRadio/Gr ... ZFPZ06.mp3
I would buy an America the Beautiful Annual NPS Pass for $80. If you like the NPS/BLM/ACE type places, it will pay for itself after 8 entries to them. You can get them at most NPS park entrances.
There are lots of lookouts/pullouts along the east/west road into GC Village from Cameron, AZ. There's less to see along the southern access road in from Williams. Except some old aircraft at an airfield just south of the park, if you like old planes. Assuming you're coming along I-40, I would head north along US 89 from Flagstaff towards Cameron, and then take SR 64 west to the Village. Better scenery along that route.
Mather Campground is $18/night last time we were there. It has coin operated laundry and showers, and a free dump station, and free potable and non-potable water. The sites are unserviced, except for maybe a picnic table and a fire pit. There are bathroom buildings located throughout the camping area.
There is a serviced (more expensive) campground as well, but we've never used it.
Stock up on everything you might need in Flagstaff or Page Arizona before you go into the park. Tusayan, which is the little town just south of the park, is very expensive. For everything. The stores inside the park are also pretty pricey, as you might expect.
US89 is under repairs after a landslide south of Page AZ. I believe there was a detour route established shortly after the original problem last February.
http://www.azdot.gov/projects/north-cen ... e/overview