You'll want to get familiar with the terminal. While there are ways to do almost anything you'll need to do using GUI's, the Terminal is a very powerful tool in *NIXes. It'll take some time, but it's not too bad. For example...
[cpp]sudo apt-get update[/cpp]
Will download all available updates. You will be required to input your root password.
[cpp]sudo apt-get upgrade[/cpp]
This will install the downloaded updates.
It's a bit strange, but it's fairly straight forward.
Alt-F2 is the "Run" command, if you used that at all on windows.
You can set key-bindings in System > Preferences > Keyboard Shortcuts.
There's a lot more out there, but there's a few tips to get you started