We currently have a kitten that DD14 found (along with his sister, unfortunately she wasn't healthy enough and she didn't make it) with no Momma Kat, so DD14 is now Tigger's Momma Kat. lol We also have 2 other cats (about 6 years old) and 1 mini doxie. The cats go in and out (one is mostly out, the other comes and goes as she pleases) so their litter boxes are outside, they each have their own. The kitten does not go out (he's only had 1 set of shots, his next set is next week) so his litter box is in the bathroom. Right now it does NOT have the top on it and he kicks out very little litter, just what it takes him to jump back out of the box.

As he gets bigger we will put the lid on it. Previously when we had a cat that lived inside (DD22's cat) we had a cat door in DD's bedroom door and a cat door in the back door so the cat could go in and out to the litter as she needed to but we aren't sure how we will do it with Tig-Tig just yet. He's still small so we have time to decide. So right now his litter box is in the bathroom, not covered.
He really likes the lattice balls with the bell inside, he will chase those around for ours, he also really likes his puff ball on a spring toy, it's got a flat bottom with a spring (covered with plastic) with a fuzzy ball on the end, he jumps all over that thing, he also loves his little mouse that has a string attached and hangs from the back of one of our bar chairs, it makes a funny squeak noise when it moves and he loves batting it around.

I also got him a toy that has a ball that he can chase and some carpet in the top for clawing but he doesn't use it much so I think I'll return it, I've only seen him play with it once, otherwise it just sits on the floor and gets ignored by all the cats and the dog. LOL Every cat likes a different toy so you may have to trial and error a few and yes, a scratching pad is a good idea, if I do return the toy Tig isn't using I'll exchange it for a scratching toy instead.

If not he'll get a scratching toy from Santa this year.

Beds, Tig "stole" Autumn's donut (it's a cat donut but since she's so small it works perfectly for her) that is in the living room so we got him his own.

He has one in the bathroom (where we put him if we are gone for extended periods of time during the day) and one on his Momma's bed, sometimes he uses the one on the bed but most times he curls up next to DD and sleeps with her.

For fleas we use Advantage, he was covered with fleas at first so the vet gave him a drop of Advantage and instructed me to do it again a week later, he's flea free now and will get regular doses with the other cats. Our vet lets us buy a large dog tube of Advantage and we are able to get several doses for the cats from just 1 tube.

We have a syringe to dose correctly and a bottle to keep the extra Advantage in, not all vets do that but ours does and we love it.

As for the doxie, she honestly thinks that Tigger is hers. Since we have cats she's used to them and is fine with them, but she chases Tig all over the house, plays with him, bathes him (we only had to give him a few baths because Autumn was always making sure he was clean, which was nice because they were 4 weeks old when we found them), and protects him from the other cats.

We didn't "introduce" them really, we just let them approach each other and do it themselves, we were very lucky because Autumn was not aggressive at all. I'm not sure I'd do it that way in your case, do you have a baby gate you could use to keep the kitten in 1 room and the dog in another, then you can introduce them that way.
Good luck, kittens are loads of fun but a lot of playful trouble, after time that passes tho and you have a furry friend to share your life with.
