As far as the bandage goes - everyone's different. I had surgery on Wed (with a big bulky bandage), went home on Sunday, the bandage came off on Tuesday, and the stitches came out the next Wed (two weeks post-op). I begged my doctor to take the bandage off before I left the hospital (more for me than for the kids - that thing was dang tight!), but he wouldn't. I'm sure he had good reasons for waiting, but I can't now remember what they were.
My kids were 4.5 and 1.5 at the time of the surgery. I told my oldest that there was something growing in the very deep inside of my ear that shouldn't be there, and that I was going to the hospital so that the doctors could take it out. He knew I'd feel sick for a while after, but that I'd be fine and that Daddy, Grandmas, and a bunch of other people would be sure to take care of him and his brother until I was feeling better. That worked well for him.
Mary - obviously, you know your family and children better than anyone else here and you know what will work for them. But I'd at least consider letting them know that it's going to be a little more than just a run-of-the-mill "headache." I'm told I had an incredibly easy recovery, and I was home for 3 days before I ever left my bedroom. I couldn't stay awake for more than a couple hours for at least a couple weeks. And I couldn't just get up to help the kids with drinks, retrieving toys, or anything else we normally don't think about. By 4 weeks out, I was pretty much normal as far as they were concerned. But it definitely helped here that they knew Mommy was "still recovering". As you well know, kids are incredibly perceptive and they'll figure out something bigger is up with Mom. And really, all they want to know is that you will get back to being the Mom they know.
So, think about it. I know you'll do what you have to (moms always do!) and your kids will get through it right along with you. This will all soon just be another blip on the radar of life. **hugs**