Ha, I hope there are more smiles than frustration in the long run.
I'm not exactly sure what you're dragging and to where. To load music onto your iPhone from iTunes, you just need to sync the two using iTunes. One of the best ways to do this is create a playlist in iTunes that is only for media you want to sync to your iPhone. Then, in the sync prefs, select that playlist as the only one to sync. I like to make a smart playlist that pulls a random selection out of my larger library, so I am surprised every once in a while.
Just connect your iPhone to the Mac Mini. iTunes should launch automatically. If it does not, you can always open iTunes manually. Then, set up your sync options and sync away.