Everyone knows you can use SSH to tunnel traffic through a remote host running an SSH server. This can allow you to use the web, for instance, as if you were at that remote host. You do this by creating a SOCKS proxy and then setting your local browser to use this proxy.
$ssh -D 8888 username@remotesshserver
This command tells your machine to create a tunnel to the remote ssh server and create a proxy on your local machine at port 8888 for you to use.
Now all you need to do is configure your browser to use this proxy.
Server: localhost or 127.0.0.1
Port: 8888
Although using this proxy through firefox will secure your web traffic, it will not hide your DNS queries. With SOCKS 5 in Firefox you can specify which side of the proxy handles DNS lookups. This can be done by setting network.proxy.socks_remote_dns = true in about:config.