go here, read this first then print yourself a copy of all the section
remember you can not "break " a bike by turning the suspention knobs, however if your not carefull it can help you to crash....in other words... take it freaking easy after every adjustment. the link has good info and the section on diagnosis of a problem is good however its not the end all.
all those suspensions parts are ment to be turned, you can always go back if you write them down
forget all those setting you find in magizens, properly tuned suspention for one guy on one road at one speed is not correct for the next guy.
make two clicks of adjustment at a time on comprestion and rebound. that way you can feel it for sure, if its to much go back one.
preload-if you dont set it your pissing in the wind...so get two or three of your buddies to help you do it right.
after setting preload
generally compression and rebound are a ratio, start with compression (thats the bottom screw ussually) and go all the way counter clock wise, then count the total number of clicks in (going clock wise). write down the freaking number of clicks...(or you will wish later you did). go all the way counter clock wise again and come in 1/3 of the number of total clicks
rebound, ussually the top screw, go all the way counter clock wise and count the clicks (or turns if you dont have clicks) back to full clock wise...from there come back 1/3 of the clicks.
the books all refer to hard soft, think of is as fast slow. compression effects how fast or slow the forks compress and decompress, ussually fully counter clock wise is the fastest/softest. fully clock wise is slowest/hardest. you dont care about hard or soft, think fast slow. if the forks dont compress fast enough your bike will ride hard and rough, sliding or spining tires may result. fully clock wise on rebound is ussually the slowest to let the fork decompress to normal ride hight. if the fork goes in fast it needs to come out slow so you have a smooth ride and the bike does not pogo. that is why you are at 1/3 in on compression and 1/3 out on rebound.
thats a good place to start
if you had 20 clicks of compression and 10 of rebound then you would ....
on compression from fully counter clock wise come clock wise 7 clicks (yes you could use 6 to..but stay with me)
on rebound you would go fully clock wise and go back counter clock wise 3 clicks
7=1/3 of 20 (or as close as you could get)
3=1/3 of 10(see above)
now thats a starting example, your bike is prolly different. if you were at 7 and you thought the front dove or was spoungy then go to 9 on compression, because 20 is 2x10 every two clicks of movement on compression you should move one click of rebound. you slowed the compresion down (by turning clock wise) so you should speed up rebound by 1 click counter clock wise (remember that turning rebound fully clock wise is the slowest recovery rate, if you set it there and push on the bars you could prolly watch the forks recover)
thats a simple set up. set your bike up and then take an easy ride, 70-80%
see what you think, make adjustments...you wont break it trust me. take your time, once you think you have it ride it a couple hundered miles.
then try this
generally following the above principals, go through every possible adjustment combination there is, you only need to ride them a half mile or so each. but you need to do this to learn what will happen when you make an adjustment. if you dont then you will think you are riding on the best settings and your not even close. take it easy when you do all these adjustments but it will pay for your time.
dont be afraid to make changes, you can always go back (need i say again ... write that _ _ _ _ down
on my bike i have 0 compression and about 1/3 rebound dialed in, so the above is a starting point with a means and method to learn your bike, not all bikes are the same, nor riders, nor roads or tracks. whats right for your buddy at race pace may wreck you or vs versa.
proprely set suspension will make your bike ride smoother, inspiring your confidence, make tires last longer and make you faster and safer.
hope this helps