I'm going to school to be a vet tech and in addition to that, I've raised kittens from birth to 8 weeks or for life...
You can either use a syringe, eye dropper, or you can use a kitten/puppy bottle...sometimes bottles are really hard to use, so make sure you cut a hole in the nipple to get a nice flow going when they suck on it.
Kittens have energy to get them crying for food and to grow...that's about it, so you have to keep them warm because they don't have much energy left over to generate heat. Get a heating pad and place it under a blanket for them. The temp should be around 88 - 92 F for them at all times. Until they are about 5 weeks they are going to need the room to be about 80F
Babies can get dehydrated really fast, so you have to make sure they are getting fluids around the clock.
To feed them you place them on their stomachs on a towel or blanket...something they can cling to. Open the mouth a little and get the nipple in their mouth. I like to make sure there is a little milk on the tip of it already to show them that its yummy. Hold to bottle at a 45 degree angle to keep bubbles out. They should start suckling (if they don't, let me know and I can talk you through a few other things to help out). If it chokes and sucks it into its lung you need to hold it upside down right away until it stops. When the baby is done eating it will either pull away or get little bubbles by its mouth. Also, a full kitten will have a nice little belly.
Make sure formula (go get some KMR at Walmart!!!) is warm, but not hot. You need to feed them every 3 - 4 hours (its actually not every 2 - BUT if they are crying for food, give it to them). The KMR will say how much to give them at a newborn age. But as a general rule, they need 8cc's of formula (mixed formula with water) per ounce of body weight.
When a kitten is done eating you MUST burp it. Just do what you would do with a baby. Also, get a damp cotton ball and wipe their little parts. They need to poop and pee for you often. Pee after every meal. Its messy, but it HAS to be done for weeks...they can't do it on their own yet.
By a week of age you can feed around 30cc (30 - 35) a day, 6 times.
Also, do you have a kitchen scale?? You NEED to watch their weights.
Keep us updated!!