I'll answer based on DS (8) since DD's visits with her dad are sporatic.
How often do you tell XH about things: We email as stuff comes up. So if parent/teacher conferences are scheduled I shoot a "p/t on Monday at 4" email and he is responsible for putting it on his calendar. For sports and stuff, we tend to email about what activity he is interested in and one or the other agrees to sign him up. Thus far, I've picked up all the fees for extracurriculars but that's because I can. XH has access to all school stuff online and if I get an email from DS's teacher, I just forward it on so he has the same info I do. We also email all conflicts with visitation. I rarely talk to him at all in person!
Homework: DS goes straight to XH's on Friday's and homework isn't usually done over the weekend, so we do it when he gets home on Sunday afternoon. It's annoying but not the hill I plan to die on.
What do I send when he visits: Nothing. He has his own clothes over there. If I know he wants a certain shirt or something, I send that, but that rarely happens. Winter stuff may go back and forth, but most of the time it was already in his backpack from school. Oh, and sports gear will go back and forth since games tend to fall on Saturdays.
Sorry your XH is too busy being "fun dad" to be a parent
Jake is 3...so we haven't gotten into the school thing yet.
1. I send emails about once a month regarding things that Jake is doing. He lives 3 hours away, so it's not really possible for him to come for everything.
2. Homework is non applicable. However, my son goes to his dad every other week-end. I don't really expect his dad to spend too much time doing homework when they only have four days together. Plus, he'll be going to french school and his dad doesn't speak french. I suppose we'll find a solution when we get to it.
3. He had clothes at his place for our son. Normally he sends our son back in an outfit that I wash and send him back in. Once in a while, I'll send him in one of my outfit and I pretty much always get it back. (unwash, but not a big deal.) We share all outdoor stuff (coats, boots, shoes, hats..etc.)
And because I read it fast and missed the part where he doesn't see the kiddos regularly, I'll tell you DD's stuff too!
How much do I tell him? Not a ton because he's not involved in her world outside of her visits with him. He gets emails from her school and teachers directly, so he's made aware of educational stuff that way. She's not into sports, so that's a non-issue. I've offered up information on stuff like her counseling, but he never asks about it, so I've stopped telling. When I drop her off I give a brief report of what's been going on and answer any questions he has.
Homework: She does it all at home. He's not involved in this at all.
Stuff: Since she goes so infrequently, she packs a big bag for the weekend and brings it all back to be washed. Not a huge deal since she does her own laundry at home. He'll ask her to bring specific stuff if they need it for whatever they're doing.
On a sidenote, I lurk a lot on the Blended Families board on The Bump and there are some online calendar things you can set up so you put the info on it and XH has access to it. Might want to look at that as an option?
My ex isn't involved at all. He doesn't here anything from me at anytime. He visited for the first time in a year and a half a few months ago. It was just mentioned in passing what the kid was up to. Other then that, I say nothing.