I was going to suggest a mulch pile, but didn't want to over whelm you. It is very rewarding to end up with beautiful, rich soil. I have done just a mound that would get shifted back and fourth as it gets mixed. Also bought a plastic bin type thing through the local garden club. Much preferred the old fashioned first way.
Read recently that coffee grounds are very acidic, which rhododendrons and evergreens like. Not sure if it is good to put in the pile for general use. Spider Girl might know the answers to your other items you asked about.
If you really want to get into the mulch thing, red worms are a great way to go. Very quick. Bought some of those, but ended up releasing them in the yard. (Too much going on for me at that time to worry about it.)
Congratulations on your new hobby! Sounds like you are on the right track. Just be careful that you don't bite off more than you can chew and get too much going on. Keep it fun, not dreaded work!
Good gardening web site