Google Docs

I first started using Google Docs when I couldn't afford to buy Windows Office. When I needed to do some word processing, but didn't want to hike to the library, Google Docs were a life saver.
I didn't have to adapt much to start using Docs because the formatting and setup is very similar to Word.
I didn't have need to use the other Google Doc formats, like spreadsheets or presentations, until later when I was using Google Docs collaborative aspects.
As I was working on a project with a group, using Google Docs was perfectly suitable. I was able to create the document on the cloud, share it with multiple people, who could then add their own changes.