Surprised to see it here, as I assumed that everyone on HN would know already how to use ssh proxy.
Nevertheless, in my experience Firefox works astonishingly bad with it. From time to time (probably, as some connections expire or whatever: I'm pretty sure it depends on network configuration at your location) Firefox just stops responding to user actions. It doesn't really freeze: buttons are clickable and you can open a new tab, but clicking on a link or entering a new url does nothing. No errors, simply nothing. I never filled a bug report, as I cannot actually work out what happens or how to reproduce it, but that thing happens to me only when Firefox is working through SOCKS 5 via ssh and it's frustrating as hell.