Assuming your question is about how to wirelessly trigger your flash using your 7D...I dont have a 580, but here is what I do with my 430.
1- Put the 430 in slave mode. Its written in the manual or check online how to do this if you dont know
2- Make sure the transmission channel on the flash is the same as in the camera
3- As the wireless functionality requires line of site, make sure the front of the flash (where the red box is) is facing the camera
4- Popup the built in flash on the camera. If this isn't done, I think portions of the menu aren't available.
5- Once the built in flash is up, then head to the Flash Control in the menu. Towards the bottom, you should have a section for Wireless settings. Go in here, and select the setting you want based on the little pictures
That should be the basics (if I remember it all). There are other things to explore such as 2nd curtain shooting, flash exposure compension and so on.