This is just a brief set of instructions I've left for friends to follow, instead of me repeatedly explaining the same things over the phone. If you're looking for in-depth tutorials on this subject, you'll want to look elsewhere. This page is mostly about FC7, and I've another page with generic hints on how to start installing software on Fedora.
After installing Fedora 7, I spent a few more minutes installing some software that I wanted that doesn't come with it, but versions for Fedora are available from the Livna repository. There are other repos (e.g. Fresh RPMs), but I'm not familiar with how well they work, and it's quiet problematic to mix them together.
You can set up Fedora to use the Livna repo by visiting their site, clicking on the Fedora 7 repository RPM link, and following the dialogues that pop-up through your web browser. You'll get double-prompted about installing it if you don't have their GPG signature key. You can go ahead then sort the key out later, when you install software from their repository, or you could sort it out first (though I couldn't see an easy way to get it manually mentioned on their site).
Alternatively, as the root user, you can use the command line to set up the repo, but you'll still have to sort out the keyfile (yum will do that for you when you next use yum).
After setting up yum to use Livna, I did my software installing through the command line using “yum” as the root user. Though there's several other ways of installing software, this is the most predictable tool to give instructions about for those who've not used any of them. If you don't have their GPG key installed by then, you'll be asked about it by yum, and it'll handle installing it for you.
Installing MPlayer to handle various different media types, launchable from the command line, also as a GUI player, and a player for media embedded in webpages:
Installing another media player, VLC (it's often useful to have alternatives, some programs are better at some things than others):
Installing another media player, Xine (as before, it's often useful to have alternatives):
NB: This time, I didn't bother directly mentioning “xine” in the packages to be installed, just for the sake of typing laziness, and to demonstrate a feature of yum. Yum will get it, automatically, if it needs to (if it's not already installed, and if it's a required package for the one that I did ask for—which it is). I could have done the same for mplayer. When you install something with yum, it gets everything else (that it can) that's needed.
Adding MP3 support to the XMMS audio player:
I could have installed the lot in one time, just listing everything I wanted on the one yum command line. They're separated, here, for the sake of keeping different programs explained separately from each other.
Installing Macromedia for Firefox, at least (I haven't checked what else, also, gets it at the same time). As always, become the root user, get a repo file from the one external place (http://macromedia.rediris.es/) authorised by Adobe to provide Macromedia (Adobe's own site wasn't any help to me when I last tried), install the flash-plugin, then unbecome the root user as soon as you don't need to be root anymore: