How to get photos of kids jumping on a trampoline with a nice brokeh background?

I’m using a Canon 30D with either a 17-55 IS lens or the 24-105 IS lens. This is going to be shot outdoors. What is a good setting for my camera so I get a good clear photo when the kids are jumping and a nice brokeh in the background? I understand it has to be fast so that I get the kids in mid-air and not blurred. And, what exactly do they mean when someone says a “fast lens”. Does that have to do with auto focus, or f/2/8 or whatever?
Thank you for the spelling correction…that’s was very funny too!!! LOL Yes, it should say bokeh.

shoot in daylight. not at noon. that’s ugly, ugly light. But in the morning or afternoon/ evening while the sun is still out. shoot at a 1/500 of a second to completely freeze the action. if you want a clear background place the trampoline away from tall buildings, trees, towers, powerlines, etc…. if you are still around a lot of things taller than a trampoline, which my guess is there will be, bend your knees. shoot at an angle pointing up so that you can get an image of the kids when they are in the air. i have an example of a good trampoline image

go to this website:

http://www.acpworkshop.org/

click “enter gallery”
where it says 2007 at the top, roll your mouse over it and a couple of years will scroll down.
click on 2006.
and there you’ll see part of the pic. top left
you may have to sort through some of the images to see it whole, but it’s there. and it was taken by an amazing photographer.

hope this helps.

p.s.
f/2.8 doesn’t mean fast.
the glass can still be fast at f/22.
fast is how good your lens is and how fast the autofocus is.

Kids Digital Camera