Congrats on the house and garden. 6 hrs. sun is the minimum recommendation. If your bearded iris are old varieties they often accept lousy conditions.

People are going to be constantly asking for your zone. You can add it > Your Houzz > Edit Profile. It affects when you can do certain chores :-) , types of iris that will flourish, etc.

Most beardeds bloom once a year. Ideally they would be moved/divided just after blooming. Most people don't want to do that chore then and wait until late summer. They need to establish a good root mass so it needs to be done at least 6 weeks before the first frost. If you dig some root mass with the iris they will establish more quickly.

If a friend wants a bearded of mine that is in bloom, I dig it up before the last bloom fades. She gets the right iris and I can postpone dividing. Of course I leave the cut tuber area open to the sun for a day or two (to dry & avoid rot) before replacing lost soil.

Most iris growers' sites have basic culture information. Schreiner's put together excellent coverage which surpasses anything I could write.
http://www.schreinersgardens.com/how-to-grow-and-care-for-iris

What irisgal said. I find iris really don't care when you divide them. Here the guidelines say mid July when iris are dormant. It is hot & dry then of course, makes for difficult digging. Frankly, just doesn't make sense to me because it is so dry, the rhizomes just sit there anyway. They survive, but I really feel they do better to divide earlier, or even later. I have divided as late as November & gotten a bit of bloom the next year.