So you've just installed Ubuntu 9.10, the cute and cuddly Karmic Koala, but now you're confronted with a most pertinent question, "What do I do now?" Ubuntu is a very complete and full-featured Linux distribution, but no operating system can come with everything you want.
There's much more fun to be had in what comes after installing the OS on your machine: now you get to set it up with all the best software it didn't already come with!
This list of the top things to do immediately after installing your newly acquired copy of Ubuntu doubles as a general list of great software to try out and use, complete with links to any special instructions on how to set them up, Terminal commands for those who prefer a command-line interface (CLI), and when available, personal package archives (PPA), repositories to keep the applications at their newest version, not just the security updates provided for you by default.
Repositories can be added easily by clicking the "Add..." button in the "Other Software" tab of Software Sources and entering the provided APT Line. Feel free to pick and choose; enjoy!
All here: The Silent Number: Top things to do after installing Ubuntu Linux 9.10 Karmic Koala