The inspiration is from here and the man page for ssh-agent.
Assuming you are using csh/tcsh
1) Add the following to .cshrc -- eval `ssh-agent -c`
2) Then everytime you log in run ssh-add to load up your private key
3) when you ssh to the remote machine use "ssh -A" to forward your authentication details over
An alternative is to use ssh-ident from here. All you have to do is modify your .bashrc (or .cshrc or .zshrc) to have: