Well i have never used 2088 888( jokes ) The air on the top is the air preload, If the forks are too soft add a few psi into each leg and that will harden the sping up a bit, If there too hard take some out but you will have to look in the manual to see whats the max and min pressures, As for the rebound just have a play with if until it feels good to you, Too much and you will find yourself bouncing off everything and too slow you will feel very slugish ect. As for the compression again you will just have to have a play with it until it feels good, Most people try to run None to a little compression but its up to you.
1 thing that you can do is the tie a cable tie around the stantions then go for a run down your local Dh track and see how much travel you have used, You want it to be fairly close to bottoming out so that you are using the full tavel. And if you are not close to using the full travel take some air out and if you are bottoming hard youll need to add some air.
hope I have helped
Chris
