Hi! I'll do the best I can, and I am sure someone will pick up the slack! And welcome to Irises! (By the way, I love Blue J Iris! They always have a great deal.)

Most all Bearded Iris love sun. I've seen some do alright with part sun, but they will not usually multiply as fast. 6+ hours a day in full sun do them best.

I just put in a new flower bed for a large collection of TB's and used a mix of Humus, top soil, and compost. Mostly compost and top soil though. I think I only added about 2 bags of humus to the 7 bags of the others. All the Iris already in the ground are rooting, and some are showing new growth.

To plant them, you need to dig a hole deep enough for the roots to be spread out, but so the top of the rhizomes are just above the level of the ground. Slightly out of the soil. Just make sure to get them in the ground 6 weeks before the usual first frost!

Mulching is not a good thing for Rhizomes, at least from what I read, but I've never been one to mulch much either. Since the top of the rhizomes need to bask in the sun, it would make sense that the mulch would choke them out.

As for the bone meal, I would add some now, before you plant, and mix it in a bit OR wait until fall to sprinkle about. (This part I am not 100% on, as it will be my first year to add fertilizer. Mine has bone meal in it, and the only real instructions are "do not apply directly to the rhizomes" so I am still learning the fertilizer area. )

As for watering, you want to water deeply, and not too often. The rule of thumb I use is if the top two inches of soil are dry it's time to water. I believe with first planting, you want to water twice a week for the first 2 weeks, about an inch, and then just back it off to about in inch a week, or less.

Irises are pretty hardy. If you over water, you get rot, so just try to find the happy medium. Other than that, they can thrive. The people on here are very helpful if you run into future problems too.

Hope I helped! Happy planting!
-Liz