if i put up a ufw firewall on this 12.10 server, what ports would i have to open?
8332 and 8333 come to mind but what about 3333?
Depends what you are doing? and where is the server. (e.g. is it at home or live on the net somewhere)
But you will need to add the pool server 3333 also its stats port if you wish to use it 8889
Also the 8333 bitcoind port.
JSON port isn't needed unless you have software outside accessing it.
If the server is hosted somewhere you will have open up ssh port to allow access to ip from where you are accessing the server from(if you don't have a static ip at home this gets complicated).
Make sure you create ssh keys and turn off password authentication. (google open ssh keys ubuntu) for how to do it. Make sure you test it or have easy access to the machine before you disable password auth.
If its live on the net somewhere please make sure that the pool and bitcoind are running under their own nologin usernames and definitely not root.
Id recheck the payout address on a regular basis as well. Don't use a address from the local wallet on the machine, use cold wallet with a watch only address.
The list is semi endless on securing it. If its for mining for others as well get help.