Hi Pwinget -- welcome to our Iris group!
Lucy's advice is spot-on. You asked a couple of other questions: 1) Yes, it's OK that the leaves have yellowed a bit where you have cut them; 2) Now is a great time to separate your Irises and transplant the increases; 3) Yes, it's OK to leave them where they are for another year -- you may sacrifice some blooms in doing so, but the Irises will probably be just fine. It wouldn't hurt to feed them now -- something as simple as sprinkling alfalfa pellets around them will give them extra oomph for next Spring's blooming season.
Irises love sunshine, good drainage and space to grow into. Provide those three things and they should do beautifully for you. I can't wait to see your pictures next Spring!!
P.S. I don't' consider Irises high-maintenance -- just the opposite, actually. Properly planted, and a little bit of annual care, and they shouldn't need anything more than thinning every three or four years.
