For ease in doing this, especially from ms-windows which otherwise makes it difficult, you can connect to your CSLab home directory using either the "Samba" (ms-windows) filesharing protocol or the Apple filesharing protocol. "Samba" is also commonly used from linux and other platforms.
From MS-Windows you can access your home directory using the path name
\\smb.cs.toronto.edu\username
, substituting your CSLab user name for "username".
From a Macintosh you can access it using the mock URL afp://smb.cs.toronto.edu (but see below)
Note that your computer will likely fill in your local user name and perhaps even your password, so you have to override them with your CSLab user name and password.
For MS-Windows, please see backup software suggestions at freefilesync.html
For Mac OS X, linux, or any other version of unix, I recommend doing backups using rsync, which can connect to your CSLab account over ssh, so you don't need to "mount" your home directory as above.
This is for doing things like backing up large subdirectory hierarchies, e.g. all of your source code. If you are in a situation where you are manually backing up individual non-huge files, you could still use filesharing as above, but actually I would recommend just using a file transfer program of some kind. I have some GUI file-transfer program recommendations on the recommended-software page.