Reply to Low budget music producing

The summer will be long, boring, badly emplyed and ill funded so, with nothing better to do with all my friends in the army or doing honest work, I decided this summer I'll start learning music producing... FOR (relatively) FREE!

I've looked around the internet and I have decided to use Ardour as the DAW and hydrogen to compose my beats. Can you recommend me free synths (that work on Mac OSX) that I can use . I'm planning to make summery/disco vibed houseish music, using samples and organic sounding bass, with some ethnic percussion and elements like violin and piano and live guitar etc. Basically it's all about the journey, not the destination, as I just want to learn to use the software and to learn sound/song/beat construction, FX usage, compression, EQ and mastering.

I believe I'll need just the minimum amount of applications (but enough to build complete tracks out of them) for starters so I can master those before moving forward.

Recommend free (or very low budget) synths, drum kits(or samples, not loops necessarily, but single drum sounds), percussion sets, effect plugins etc.

Recommend literature I should wrap my head around (or type of literature), what should I learn apart from midi?

Give any tips/tricks you want to share?

This thread isn't necessarily just about me, I'm sure there are plenty of people here interested in making music with a scant budget!