The first thing to do is make sure that any houseplants you have are non-toxic to cats, because as it turns out, most common houseplants are toxic to cats!

For litter boxes, I would recommend you have a sealed wastebin nearby to immediately scoop and dispose of waste. Immediately scooping and containing/disposing of waste is the best form of odor control.

In terms of food, I would begin with a steady diet of wet food, unless you're limited by budget. If wet food is not readily available, you could also mix warm water into kitten kibble or microwave to create a wet paste that's more easily eaten and digested by your kitten. Regardless of which method you use, I would steadily start introducing more and more solid food/kibble until they're on a steady diet of mostly solid food/kibble with some wet food mixed in.

Casa Inc has good advice. I used a basic plastic tub as a litter box. I found that using a very low depth of litter, frequent scooping, and weekly washing of the tub helped keep odor to a minimum. I would not use a scented product, and I would consult a vet before considering clumping litter. Your vet is also the best source for food advice. It is easy to overfeed cats as they age out of the kitten stage and their caloric needs change. I learned that the hard way!

Cats can be persnickety about things. As you get to know kitty, you’ll learn whether my litter technique works for your foster, or if you need to increase litter depth, or get a covered litter box, or make other adjustments.

Don’t leave string or ribbon toys out for unsupervised play. A swallowed string or ribbon can easily kill a cat. Save those toys for when you play with kitty.

You might enjoy the Love and Hisses blog. Robyn Anderson has been fostering kittens for at least a decade!
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Here's a litter that my roommate and I have recently been using. It's a little more expensive than your run-of-the-mill, bottom shelf litter but it's been great so far. The litter is formulated from tofu and due to the size and shape of the individual pellets, scooping does not kick dust or other particulates into the air (with other litters, I always have to hold my breath as I'm scooping).