Some friends and I ventured into the NF in late May at around 10,000 on the Canyon RS gauge. The paddling and camping options in that canyon at that flow are incredible. Both Skull (IV) and Orogrande Creeks (V) were running and the 420 Hole was in. As others mention, the NF itself is Lochsa-esque III/IV big water with one obvious V at Irish Railroad.
Skull Creek features boulder rapids in a tight channel. There are two notable rapids. First is a two-part boulder drop with a great flare boof (check for wood in both parts). The second is a constriction followed by a weir-like pourover. You can scout most of the action from the convenient road next to the river. We put in at the bridge, but rumor has it that more action lies upstream.
The lower two miles of Orogrande Creek consists of low volume class V boulder gardens with a few bedrock rapids for good measure. Wood is in play in almost every rapid, so be on your game. That said, there are no mandatory portages and many excellent boofs. The crux comes at the bedrock gorge half-way through the run. Staircase ledges lead to the lip of a 30 foot low angle slide with a hungry hole. Below this gorge, fun runout drops lead you to the Clearwater. As with Skull, scouting is facilitated by the convenient road (seems like Idaho has a lot of these).
You could camp on either creek or split the difference and camp at 420 Hole. This eddy serviced gem will entertain beginners and experts alike. It felt pretty optimal at 10 grand. Another play feature seemed to be forming below Washington Creek, but 420 was so good that we didn't bother to investigate. It's pretty remote in there so bring extra gas if you're planning a long stay.
"A river is more than an amenity, it is a treasure."
-Oliver Wendell Holmes writing for the majority in New Jersey v. New York