I use Noteworthy because it's the "program of choice" for the guys who put tunes in the DigiTrad. It is not what I would consider an appropriate program for "publishing" music, but does a reasonable job if all you want is printed copies to use withing your group. Everyone should have it - 'cause we've still got a whole bunch of tunes needed for the DigiTrad.
Everybody needs some program that will make midis - and the free (to 'catters) Mid2Txt/Txt2Mid set, because that's the easy way to post a tune to a thread, or to email a quicky to a friend. The link that the program prints no longer works, but you can get these at MIDIText.
When you convert a midi with the Mid2Txt program, you also get an ABC. The Txt2Mid will convert the miditext part back to a midi that virtually any computer, PC or Mac, should be able to play. If you want to convert the ABC back to something, you'll need ABC software - see the threads linked above.
Miditext and ABC are both designed specifically to allow you to "send" music as plain text. This is something you would normally need to do only for web postings, although if you're clever you can probably find other uses for it.
ANY decent notation program should accept input from your computer keyboard and your mouse - whichever you choose. Most of them also will allow you to plug a synth keyboard (if it has a midi output) in and "play" the music in, if you want. ANY decent notation program should be able to print at least 8 staves, and should be able to "save as midi."
The things that separate the better programs from the lesser ones are things like: Cheaper/Freeware programs often limit you to 16th notes for the shortest "playable." Midrange (over $25 in commercial stuff) should give you 64th notes. Most low end stuff will "play" repeats (dotted bars) but may not do DC/DS and such. Most low end programs will not automatically play turns, trills, and such - you have to "note them in." Linking lyrics is somewhat variable, even with the better low end programs, but a decent program should let you put at least 8 verses - linked - in the score.
Any program will require some "learning curve." If you learn any of these programs well enough, you can make it do quite a bit. The idea is to find one that does what you want it to as easily as possible.