Google published a Grandmother's Guide to "Google Video Chat". "The video embedded below, along with a printable guide (embedded below), can be accessed at google.com/chat/grandma.
After your grandma is all set up, take a screenshot of your video chatting with her and emailg it to share with us. The first 100 people to do so will get a t-shirt, printable guide and VHS of the video (because if your grandma's like mine, she's still a cassette kind of girl)," noted Google.
Google Video Chat Guide