linuxfilter: Good place to go for help with IPTABLES firewall? I'm inheriting a linux firewall at work and can't afford much (if any) downtime. I miss the simplicity of the hardware-based one I used to have, but need to turn on the ability to do RDP on 3389 to multiple hosts and also the ability to test from inside the network. I know almost nothing about this, so I'd like a nice friendly place. linux.ask.metafilter.com?
Any good guides on getting up to speed with Linux? Specifically Ubuntu, but also general things like filesystem, permissions, installing/uninstalling software, etc. [more inside]