Protecting private data

I sometimes use my MacBook at school and need to access things like hotmail etc. Now, I doubt anyone is watching, but its good to know how to do things anyway. What I want to do is protect my information VIA a SSh tunnel going to my iMac at home.

Now, I have a program called SSH tunnel manager but I haven't had much luck with it all. I have SSH login enabled on my iMac under a different non-admin account with a very strong password.

How do I forward my internet traffic to my iMac from my school is basically what I'm asking. I know how to create the tunnel, I just don't know where to go from there.

Thank you for your time.
Cpt. Morgan