To ease confusions for those wishing to purchase an iPhone 3G on July 11, AT&T has posted videos offering information about the upgrade process for existing AT&T customers as well as new customers.

The iPhone 3G will go on sale at 8am in AT&T stores across the US on July 11.

AT&T offers a video for existing customers in which the company outlines that current iPhone owners backup their iPhone using iTunes prior to purchasing an iPhone 3G. The video also notes that voicemail will be deleted when upgrading.

In a second video AT&T advises those wishing to sing-up with AT&T for the first time to visit a store before July 11th and complete a credit check to save time on launch day.