Many people would suggest trackers, however, I'm not a huge fan of those.
I find them to be very time-consuming for larger projects.
I'd recommend Audacity (mentioned above) for a free recording and mixing program, but don't expect to be blown away.
If you really want to get into music making, you're going to want to get a quality program. And there's always demos.
I personally love Reason, and find it to be one of the most useful, time saving, and learnable programs out there. But since this is a "free" topic, I won't delve more into it.
Reason demo (it's the full program, but saving and exporting is disabled.):
http://www.propellerheads.se/download/Also, here's one of my fave freebie VSTs (a VST is a virtual instrument, in case you didn't know)
. You'll need a VST host to run it (which can be downloaded
here), but can export into MIDI (which can be imported and edited by Audacity.)
http://www.amvst.com/index.php?name=Downloads&file=details&id=39VSTs are good tools, and there's a lot of em out there. This one has over 200 presets (instruments) on it, so it could keep ya busy for a while. (I like number 8.) If you have any more questions on VSTs, feel free to PM me.