I've been to Odell twice but always seem to pick a weekend with weather that makes you want to stay in your sleeping bag!
The campsites at Odell are a little on the smaller side and may not have the trees your looking for to hang a hammock. Not that you should if you're camping any time earlier than July!
The southeast side of Odell can be subject to cold winds coming off the lake, so be sure to keep that rain fly up on your tent and a fleece handy. If you're feeling a little too chilly, the resort keeps a fire burning in the den.
There are plenty of snowshoe trails around Odell as well as some hiking trails in the Diamond Peak wilderness that also connect to the PCT. The trail we took did give us a bit of elevation gain and later some nice views of the smaller peaks in the area.
If you're planning to camp here, bring warm clothing and rain gear! It may be a bit chilly, but the nice hikes in the area make it all the more worth it to get up and get moving.