Question about Repairs for 1999 Jeep Grand Cherokee: Rubber Boots for CV Joints?

My mechanic told me yesterday that there is an axle problem with my 1999 Jeep Grand Cherokee. He tried to explain the problem to me, but I'm really confused and was hoping someone on Yahoo Answers could help clarify the problem.

He said something about a rubber boot that covers the CV joint and that it's completely missing on one side of the car and badly torn on the other. I was wondering if anyone knows anything about this part, how complicated the repair is, how long it should take, how expensive the parts are, etc. The mechanic wants to charge us $580.

I would take the weekend and help my husband do the work ourselves, but we're moving soon and we're badly strapped for cash AND time. I can't exactly afford a $580 replacement on the truck. Is this a repair that needs to be done immediately? Or can it wait a month until after our move?

Please, any help is very VERY much appreciated. If you know of any diagrams or "how-to's" that illustrate this, please provide links.