Fork travel is not really something that you should choose based on your actual height, but rather the type of riding you do. A lower travel fork is best suited for Cross country racing. For downhill, you would be better off with bigger travel. If you are a freerider (like to take 5'+ drops and other crazy stuff) bigger travel is a must. If you have average tastes, some cross-country, some technical, climbing up a hill and coming back down kind of guy, then 100mm of fork travel would probably suit you fine.
Generally speaking, coil sprung forks tend to have a very even range of motion, where as air sprung forks ramp up (get stiffer as they pass through their range of travel). Mind you, air sprung forks are easier to tune, just pump your fork up with a different pressure and you are good to go, where as a coil fork you are limited to the strength of the spring, and might have to buy a new spring to get a different feel.
Lockout means switching your fork to prevent any travel. Say you are onroad, and have no need for suspension, you can lock your fork out for a more efficient ride.
Compression is when your fork is compacting, like when you hit a bump.
Rebound is when your fork is extending, after you hit a bump and your fork goes back to fully extended.
Damping is slowing down the travel. You can have compression damping and rebound damping. Rebound damping is most important, without it your fork will feel like a pogo stick.
Preload is putting stress on the spring, so it takes more force to activate the travel of the fork.
Sag is the distance your fork compresses when you get on the bike.
Stiffness usually refers to how effectively a fork resists lateral twisting. A fork with poor stiffness will not be good at keeping the front wheel from twisting side to side or rotating left or right slightly (which makes it harder to steer a bike in the rough sections).
If you are on a tighter fork budget, something by Manitou (Black Elite) would be a good choice. If you have a bit more cash, a Fox fork is a good buy. If you are a bigger guy or like to take the really rough stuff, Marzocchi is probably your best bet. If you are looking for the lightest cross-country fork out there, Rock Shox SID is probably the one for you.
Cheers,
Juba
