Important things to know. - Never change a kitties food after you just pick them up. Kittens don't seem to have stress or adjustment issues, they do, they just hide it well. What happens is that it comes out through their digestive systems, so yes sometime you can have diarrhea the first few days. People tend to run to the vet, change their food, and really just stress the kitten out more. Give it a week before taking action.
Litter - we use pine pellets that we get from a feed store, these pellets are completely natural no dyes, no fragrance. The reason we use this is when kittens are learning to use a litter box and starting to eat, they eat everything including litter! Using a clumping litter will cause stomach upsets and could possibly form a ball in their bellies. Normally when they go home they adjust well to clumping litter. If not, get a bag of pellets, mix with the clumping litter and they will transfer over. If possible, make sure that clumping litter does not have artifical smells, so fragrance free will help.
Cat Scratching - A cats instinct is to SCRATCH. Let's face it nothing drives us more crazy then the cats clawing the side of our furniture. I know I have thrown a couple of pillows myself. To meet their needs requires a variety of surfaces and angles. Recommended surfaces are cardboard, sisal and carpet. Cardboard is their favorite because it mimics tree bark. The carpet and sisil allows the claws to hook in the same as carbaord, but it is a bit cleaner. I love this scratcher for a couple of reasons, it has two angles you can adjust, it is made of wood not cardboard so it is sturdy. Because it is made of wood it doesn't have to be a huge thing, your cats will find it hard to tip this over. We start using scratchers at 4 weeks in the mom's birthing areas and the kittens are completely use to this product. They crawl and play all over it! What I also like is that you can actually find the replacement pieces. How many times have you bought something and you can't find the exact replacements? I can't tell you how many times I tried to order the right round ones for the scratcher I use to use. I would end up buying them too big and have to cut them down. So this is easy the replacements are sold separately to fit exactly.
It is called a 2 in 1 cat scratching post and I have provided the link. And yes, to answer your questions those cats in the picture are two six month old females of my breeding!