I want to know how to change the ISO on Nikon d3000?

I can change the shutter speed (1/320 or 1/1000, etc) but to change the ISO is that the same thing? Trying to photograph boys doing football drills in daylight.

Read your manual. You have to go menu surfing since you have no dedicated button or dial

shutter speed =/= ISO

in daylight, you will want your ISO as low as possible, as it yields the best quality pictures.

If you can't find your manual (seriously, it's pretty thick but most of your questions can be answered there) here's a link for you to download it.
http://support.nikonusa.com/app/answers/detail/a_id/16534/~/user's-manual---d3000---guide-to-digital-photography

Also, watch this video and you'll see your answer at the 1:50 mark.

You will use your quick settings display menu. The button to get into that is bottom left with a picture of a magnifier on it.