If you have trouble working with one dog while you have other dogs milling around, getting in the way, bugging you for attention, here's something that will help.
http://www.youtube.com/watch?v=MfRrBH_beX8&NR=1&feature=endscreen
http://www.youtube.com/watch?v=MfRrBH_beX8&NR=1&feature=endscreen