If you want to create music but are as iliterate when it comes to musical instruments as me (save drums, but that does not help much I guess), have a look at some of the digital audio workstation programs around, or even better, their consumer oriented offsprings (much cheaper or maybe free).
These programms will let you record and arrange your own tracks. But they will also let you build tracks from sound loops, which are short records from someone else.
If you are looking at a free programm to edit and manipulate tracks, have a look at Audiocity.
Personally, I am using MAGIX Music Maker. Its the consumer version of their DAW and somewhat similar to the big names like Ableton Live (though I guess not coming close to its features). The program itself is cheap to get and pretty good, and especially intuitive for an absolute newbie to music making like me.
They also have an online store filled to the brim with sound loops. They are reasonably priced, though the cost adds up if you want to get them all.
The tool also has lots of instruments to create your own tracks without a keyboard (music instrument), just using mouse and keyboard (computer input device). Its certainly slower to record your track this way and I guess most professional musicians will cry out in agony at the thought of it, but with some time and dedication it actually does work.
Of course, as soon as you stop just using sound loops, you will need to digest a lot of musical theory anyway, even if you don't want to learn playing an instrument. Just placing some random tones at random places might sound interesting and experimental at times... most of the time it will just sound like crap!