First you divide each stack of bulbs into two piles and send one to me. (Just kidding) You are so very fortunate to get a great windfall of bulbs. Once you get them going, the glads and iris in particular are going to give you years and years of enjoyment.
When I divide my bulbs, I separate them and remove part of the green (just have you have already done) and replant them in the ground. You will want to prepare a bed for them that means if the ground is hard, break it up. Be sure you remember where you plant them, cause you don't want to accidently dig them back up later.
I have never had luck with bulbs in pots, but my sister has. You can give that a shot and see if it works for you.

You might want to prune back some of the roots and amend the soil and add a handful of bone meal when you replant. Now is a good as time as any.

The glads and the cannas will tend to work their way back toward the top of the soil with time, in my experience, so planting them as deeply as you can - well, the cannas should be about 2-3" deep, and the glads 3-6" deep - and then mulching well over the bulbs/tubers will help them survive. I find that I need to replant the glads every once in a while, or I put them behind plants they can lean on, otherwise, they get top-heavy and lie over in flower. Cannas can take moister soil than the glads, though also will grow in dryish places - they WILL multiply and spread out if they are happy!

For the bearded iris, they WANT to be almost on top of the soil, so the tubers get a good baking in the summer. I find digging a hole and then making a narrow mound of soil in the middle to "perch" the main root on top of, with the lesser roots hanging down, helps stabilize them in place. You can also make pins of cut-up wire coat-hangers, and pin them so they stay right-side up, once the hole is filled in - the leaves can make the tubers unstable.

Any of the slow-acting fertilizers meant for bulbs/flowers will help if added to the soil, if you add it to the entire area as you break up the soil; you can put down more in the spring when you see green leaves. SOME nitrogen is good, but not lots - you want flowers, not lot of leaves - so be careful with using lawn fertilizer - in fact, don't!

Do mark where you plant them - it is SO frustrating to think you have a great "empty" spot, start to dig, and dig up thriving bulbs which were entirely underground at that point! You CAN over-plant the glads, but the cannas and the iris will need plenty of room next summer.