→Download and Install Dropbox: Fixed Dropbox location. This is more comprehensive.
Go to http://www.dropbox.com. You get 2GB for free automatically.
Once you have installed Dropbox, you'll need to know where the folder is
that it will sync from. On most Windows machines, it is located inside the "My Documents" Folder.
On Linux, the default location is in the user's home folder. For example in Ubuntu, that folder is located at
Whichever operating system you are using, Dropbox has very good documentation and can assist you in finding help: http://www.dropbox.com/help