Here's some sort of explanation on how to do bunnies. It was written as a reply to an email and the answer apparently helped the receiver.

So, example setup for a player that jumps with mouse2:
bind w +forward
bind s +back
bind a +moveleft
bind d +moveright
bind mouse2 +jump
+mlook

Ok. Explaining how to bunny correct isn't easy, and explaining how to bunny good is very hard. But there are some basic pointers I hope I can give.

1. The first technique to know is the accelerating jump that nobody has bothered to think up a good name for. It's the first jump which gets the bunny sequence going, and it's where you start abusing the quake physics ;) Stand still on the ground, swing your mouse to turn 90 degrees to the right, while holding +forward and +moveright. When you've turned your 90 degrees, press +jump and immediately *release all buttons*. The 90 degree turn together with strafing will increase your speed, and you'll find yourself in a jump which is faster than ID ever intended.
     You have to get a feeling for the timing! You can't just do the jump after a microsecond of turning and expect high speed. You have to give the engine some time to apply its flawed physics to the player. It doesn't take very long at all but it does take a fraction of a second.
     Just practice doing this acceleration jump. I remember spending a lot of time on the start map just doing it back and forth back when I was a newbie.
2. The second technique is the bunny sequence. Once you get your speed, from an acceleration jump, from a slope or from a grenade boost, if you keep jumping, you'll keep moving in the direction you started off at. You have to jump as soon as you hit the ground, because prolonged exposure to ground friction will slow you down. Do the accelerating jump and then hit +jump again right before you hit the ground, again and again. You'll keep some of your initial speed but after a few jumps you'll be standing still.
3. Here comes the part which is really hard to explain. You can maintain your speed (and even increase it) if you use strafing in the air. When you have jumped, don't release +moveright (but do release +forward!!!!!). Keep it pressed, and keep moving your mouse to the right. But only for half of the duration of the jump. After the first half of the air flight, start moving your mouse to the left, let go of +moveright, and push +moveleft instead. The ground is now approaching, and you'll have to push +jump again. Do the jump, but keep moving your mouse to the left, and keep pressing +moveleft. When you reached the top height of the second jump, again start moving your mouse to the right, let go of +moveleft, and push +moveright. This sounds very complicated but after a lot of practice you don't think about it anymore, it's all in the fingers and wrists. Remember, you don't use +forward in the sequence, only in the accelerating jump.

• One thing to keep in mind is that you're supposed to always be facing in the direction you're moving. If you follow my description in step 3 you'll hopefully find this is true =)
• A bonus technique which gives you that extra speed push but isn't necessary to begin with, is to hit +forward every time before you hit the ground, and release it as soon as you've left it again. This way you'll preserve speed a little better but it's difficult and several players do just fine without it.

Good luck, hope this explanation helps! We'll be expecting to see some demos from you some day ;) Remember that the key is practice. Always practice.