for starting out, although I love ableton, it`s not the best for midi work for a beginner.
I hate reason, but in temrs of starting out, it really is a great place to start, it`s closed environment, will allow you to focus without too much distraction, and
it will also teach you about routings the old school way (albeit with virtual leads).

Fruityloops may also be a good place to start, but really, go for reason, and when you find you are ready to go onto more complex composition in a totally open environment, then it`s a matter of taste as to which package you go to from there.