"Song drafts" -- I'm not even sure if that's a thing but let's go with it.

I have an outline for a whole album and some bits and pieces written. Rather than sitting down and starting to record immediately, I'd like to start drafting out everything with MIDI or something to where I can play around with the sounds and also make notes of lyrics, chord shapes, etc. Bonus points if I can use something like Garage Band's drummer features so I don't have to worry so much about the percussion.

What's the best software or website to do something like this? I'm imagining something like Fruity Loops or Guitar Pro, where I can plug in some guitar, bass, etc. tabs and include drums and other instruments. I would prioritize ease of use and speed of composition, since these are just going to be temporary sketches.

Then, when I get the songs in a shape I am comfortable with, I will jump into the DAW and do the actual recordings.

I'm curious if anyone has any good resources for learning music composition. My situation is that I've studied music for years, including being a music student for my first 2 years of college. I got out of music for a while, and am getting back into it now. I'm interested in learning more about music composition, but have been unable to come up with good resources on the internet. I know a lot of music theory (though have probably forgotten a lot, too), and have done some basic counterpoint exercises in the past. I can string together some nice chord progressions, and sometimes even a decent melody, but developing a musical idea into a full-blown song or other piece of music is more difficult for me lately. So I'm looking for something along those lines.

If it makes any difference, I tend to like instrumental music with American pop sensibilities. I play piano, cello, and tenor ukulele.

If this would be better under the "music" group, feel free to move it there. I was unsure as the music group seems to be oriented towards listening rather than creating.