I've been traveling back and forth to Lewisburg a lot recently, doing some informal chauffeur service for a family member. Went up Thursday, just got back last night.
It's basically an hour from Lewisburg to the C&R parking lot. You can knock about 10 minutes off that by parking at the first pull-out by the stream, which is about 1/2 mile below the beginning of the C&R section.
The other access point is in Coburn, which is another 45 minutes more.
What's hatching? As of 5/16: crane flies, gray caddis, March Browns, a few gray foxes, light cahillls and sulphurs. Nothing in serious quantities, but it could bust loose any day. There's often an evening rise right before sunset. Good luck figuring out to exactly what. Also an occasional gulper in the broad daylight hours. I got a couple of fish the previous week on something big and brown and fuzzy. But I'd keep some sulphurs on hand for the next few weeks. Especially emergers.
I've found the reports on stream conditions and hatches by Bruce Fisher at Penn's Creek Angler in Weikert to be spot-on, right down to the difference in stream conditions between the morning hours and the afternoon on May 11.
http://www.pennscreekangler.com/2010%20stream%20report.htm
I got three fish yesterday morning- a 12" smallmouth and two brownies- one around 8-9", and the other around 15-16". The creek was a little murky, although nowhere near as bad as it can be. It may have cleared up by now.
It's supposed to rain some next week- if it's just scattered showers, Penn's should stay in good shape. More than that, and it will mud up for a while.
Getting to Penn's via Weikert can be a little complicated, depending on the route. Check your Google Maps, set it for directions from Lewisburg to "Cherry Run, PA". Once you're on 3002 (Weikert Road), keep going west past the Sportsman's Club, then past the Penn's Creek Angler/Weikert Post Office about 4 miles. The C&R section parking lot is at the end of the road, about 3/4 mi. west of Cherry Run itself.