I've just purchased my Ipad and brought a Belkin screen protector,(you only get one) for £2.50. I followed the instructions carefully and no bubbles. Only downside is that when the pad is off the surface looks slightly oily..
I bought the iVisor by Moshi. It came with 2 and install was easy and no bubbles. The film has a little shmootz even though I use a stylus. A drop of water and the included cloth and it gets shiny and clean.
Never covered any of my devices up til now, never got any scratches either. Did once try out a screen cover on iPad, but it was just horrible. They seem to take all the fun out of the sensitive bright screen. No never again