What the hell? Surf maps are one of the big gimmicks in CSS. It's a way of sliding around the map on slants by abusing the source engine. It's hard to get the technique at first, but after you get it you can have a lot of fun flying around maps extremely fast.

I freaking hate surf maps SCREW you contero: That's because you suck lol. Here is a mini-tutorial on how to not suck!

The first thing you need to is DON'T PRESS W WHEN SLIDING EVER Trying to move forward on a block will cause you to lose traction and just fall right off the block.

The second thing is to hold down A or D (strafe left/right) so you are strafing against the slope of the block. Even without any momentum, this will cause you to stay in place on the slope instead of sliding off of it.

How do I GO? Look at this awesome picture:

Those grey things are the block slides in the level, and the stick figure is you. The red dotted line is your line of sight if you were looking exactly parallel to the blocks. The purple line is what your line of sight should be if you want to move forward. By aiming your line of sight a few degrees in the direction of the slope, you will start to move forward using the gravity that wants you to fall off the block. This is also how you gain momentum when sliding. Usually blocks are slanted down or are stacked so that you won't risk falling as you slide downwards, gaining speed. Like this:

Another thing you should know is how to corner in the air. Some blocks are arranged in wierd ways so that when you try to surf onto them normally, you hit at a wierd angle and lose all your momentum. This sucks. What you need to do is strafe away from the block before you reach the next one. This will curve the direction of your momentum so that you are inline with the next block. This technique is a major part of surf_leet.

Remember, use only the strafe buttons and mouse to manipulate your character when surfing. Trying to move forward or backward messes up your momentum. The only time you want to do this is when you are going to fast and want to land on a target below you. Pressing S (back) in midair, no matter how fast you are going, will cause you to come to a sudden stop in the air.

At the very least this should get you started so that you don't fall down so often. Once you start surfing more you learn more techniques and get the feel of it better.

Conclusion: Surf maps are the best!