1. As long as you have your printed permit with you, you do not need to "check in" anywhere to reach the backcountry sites.
2. Almost no one we encountered had maps - be sure to print as many out prior to your trip as possible.
We parked at Beaver Basin Overlook (beware: the gravel drive in has lots of potholes!), and hiked into Pine Bluff Campground. It was about 4.7 miles in, and relatively flat. The first .5 mile was a slight decline (so it was a bit of a thigh-burner on the way back out).
When we arrived, only one other site was taken, and we all agreed we got the best site, #5 (there are five sites total). It's just a little more tucked back than the others, which were quite exposed. We were able to have one hammock up for lounging during the day and two tents. The site itself had a bear locker (people - remember to pack your food out!! Someone prior to us left food there and the stench was awful!), short walk to a pit toilet and communal fire ring. Lots of shade, which was nice. To reach Lake Superior (your water source, so bring a filter), you must climb up and down a fairly steep sandy bluff, but it's totally worth it. The views are spectacular, and it's very secluded - you'll have the beach to yourself! It's the most beautiful white sand beach, with pebbles near the water line and driftwood.
The first night, there were only three sites occupied, including ours. One site turned in early, while the other site and us built a campfire from branches we collected. Just remember you'll have to haul water up the bluff to extinguish your fire!
The second night, every single site was taken and there were two groups who decided to "squat" near the campground. Don't do this! Not only was the bear vault overflowing, you're stomping on vegetation in the area.
For our day hike, we headed west along the lakefront. The hike to the Spray Falls overlook and back was just under 10 miles.
The night sky was super clear after moon set, and we enjoyed tons of stars, the Milky Way and Perseids Meteor Shower. Highly recommend this campsite for anyone looking to backpack along Pictured Rocks National Lakeshore!