As more stuff goes into this poorly understood system called "the cloud", be sure you know how to back up your own stuff on a regular basis. Never send into "the cloud" anything that you don't have your own copy of, unless the permanent loss of that information would be no big deal for you. Clouds are, by their nature, transient. They disappear without warning. They do stuff from time to time that you wouldn't expect.
Back up all your stuff that's in the Cloud.
You can export your whole set of Facebook data by following these instructions:
1. Click on the triangle for the drop menu at the top right side of your Facebook home page.
2. Click on "Account settings" (or just go to https://www.facebook.com/settings)
3. Click the link that says "Download a copy of your Facebook data."
4. Click "Start my Archive"
5. Click "Start my Archive" (again)
6. Wait for the email from Facebook.
7. Download the zip file with all your data.
For Google stuff, go to the Data Liberation Front and follow the instructions at: