Our family has owned a cabin there as far back as I can remember. You use to be able to say that 4lb+ fish were plentiful. Those lakes use to be my favorite. We use to spend at least 5-6 weekend up there. That is until the shad got out of control. They have been trying to get it under control. The The big fish are getting huge off of the shad but they have over invaded. The lake is coming back the past few years. We have caught a few over 8lbs out of there, lots 5-6lbs.
I think your timing will be right if you want to catch brookies. They are awesome fighters in that lake and good size. Find a place where water is running into the lake. Throw and retreive an 11g black and gold floater. You will have fun.
Bass fishing will not be so good in May. It is the most fun when the tulies break through and the fish are in shallower water. One of the best top water lakes I have ever fished. In may go find the rock point in the north west corner of the north lake. Fish a sinko/diver/texas rigged salamander/jigs(chartruse Kalin 3"

) in 20 feet of water. You will catch some good ones.
Dont know what the regs are like this year but dont be afraid to keep a few limits of the 9-12" fish. That is what those lakes need. There are too many little fish. Them little buggers make for the best fish fry anyway. Thow the big ones back.
Have fun!!! Let us know how you do.