I found several blogs about Google Docs & Spreadsheets, but I wanted to read reviews about the program from technology experts so I searched the PC Magazine online and found a short article.
Wikipedia also has an in depth definition and even includes a picture of what a Google Doc page would look like to the user.
Google has several blogs that discuss Google Docs including a new feature called Presentations where you can create slide shows. This is a great tool to use in the classroom for lessons and even for Back to School Night presentations for parents.
Another Google Docs & Spreadsheets blog: http://googleblog.blogspot.com/2006/10/better-together-docs-spreadsheets.html.