Lake Superior is the largest freshwater lake in the world by surface area. The water is always cold, and the air temperature is rarely warm.
Pictured Rocks National Lakeshore is about a 40 mile shoreline of Lake Superior. The actual "Pictured Rocks" portion is about 15 miles (in a straight line) of high cliffs with interesting rock formations and waterfalls. There are small caves and arches, very large amphitheaters and two very large arches extending out into the water. The remainder of the park is made up of "12 Mile Beach" (about 12 miles long) and "Grand Sable Dunes".
Cell phone service is non-existent throughout the park, so a marine radio is advisable. There is fairly heavy kayak traffic between Sand Point and the Mosquito Beach area. Past that, you'll likely only see cruise ships, and past Spray Falls, you'll likely be completely alone until you reach the Twelvemile Beach campground.
The actual Pictured Rocks cliffs run from just past Sand Point right up to the Coves Campground. In this portion of the park, the only exit points that could be used to hike out are Miners Beach, Mosquito Beach, and Chapel Beach. At any other point exiting the lake is pretty much impossible due to the high cliffs.
Sand Point has an actual boat ramp, but very limited parking. It also has several beaches and it is usually easiest to just carry your boat to the water from there.
Miners Castle is the access point used by most kayakers, including the outfitters. It requires a carry of several hundred yards, and down some stairs to access the beach. But it gives the most immediate access to the cliffs of Pictured Rocks with Miners Rock just to the West (as well as many other small caves), and the remainder of the cliffs to the East.
It may be possible to use Beaver Lake as an access point by using the boat ramp at Little Beaver Lake and paddling out to the trail that connects to Lake Superior, but would involve a 1/4 to 1/2 mile carry. This would give the best access to the Eastern side of the Pictured Rocks cliffs if you were doing a day trip, the only other option is about a 15 mile paddle in from either direction.
Twelvemile Beach Campground
The banks here are high, but useable as an access point.
This is an easy access point with ample parking and a short carry to the water. But is far away from the cliffs of Pictured Rocks (15 miles).
This is about a 200-300 foot drop, but you'll see kids sliding down and climbing back up. It could be used as an access point in an emergency, but don't plan on sliding down in your kayak unless you plan to kill yourself or others in the process. It's also far away from any of the scenic parts of the park.
Grand Marais boat ramp
This is a real boat ramp in a protected bay which should make for an easy launch. But it's far away from the most interesting parts of the park.
There are numerous back country and drive up campsites available. Camping is only allowed in designated sites. Most of the back country sites are accessible by both boat and foot, but you'll likely end up leaving your kayak unattended on the beach as most of the campsites are inland. Mosquito Beach and Chapel Beach are the only beach camping areas available and do not allow campfires.
Most of the drive-in campgrounds are also accessible by boat.
The NPS website has maps and other useful information. Free (non-waterproff) maps are available at the park office in Munising. They also have several guide books in their bookstore, though they are mostly geared towards hiking and backpacking.
NPS website: http://www.nps.gov/APis/index.htm
The National Parks Service recommends having a weather radio available. However I've found that even weather radio isn't available in many places. So you have to plan ahead and have contingency plans if the weather changes.
Wave height http://www.crh.noaa.gov/greatlakes/?l=ls&p=a
Nearshore forecasts http://www.tidesandcurrents.noaa.gov/ofs/lsofs/lsofs.html