Google provides free lessons on it’s Google for Education Website. Lessons run from 15- 30 minutes and are broken down into modules. There are short videos included and you can easily choose to move from one lesson to the next or between basic and advanced lessons.
Another fun way to improve your Google prowess is to visit the Google Ninja Program. This program started as a way to help students show mastery of Google Apps and now has expanded to an online learning site for students and teachers alike. The courses include videos and tasks to help you cover the main skills before you move on. If you need help there are forums where you can post questions and find answers.