Feeding calves- New born calves need 2 quarts of milk/milk replacer per feeding for a 100-115 pound calf-smaller breeds it's usually 1 1/2 quarts per feeding. Read bag of milk replacer for amount of milk replacer to mix with water as it varies by milk replacer. Feed them twice a day. As they get older you will need to increase the amount of water added to the milk replacer for the mix. The sides of the calf, where the indent is, should be full but, not rounded out or really hard.
Have some grain available to the calf. I use a 8qt pail and as they get eating grain I cut the milkreplacer back-slowly. By the time they are eating roughly a pail full a day they are ready to come off milk replacer and go on water. You can then start adding hay to their ration. This usually happens around 2 months of age, some a little sooner and some a little later. The recommendations are one 50 lb bag of milk replacer per calf, again it varies with the calf.
Calves are born with two stomachs working and as they slowly go on grain they start developing the other two stomachs. Therefore, you don't want to push had to them until they are eating grain good because they won't be able to digest it properly. Yes, a cow has four stomachs!
I also start my calves on pails at about 3-4 days old. This not only makes it easier for you-nice bonus-but it keeps the "suckers" (calves wanting to suck after weining) way down. Since I started doing this, about 19 years ago, I haven't had any trouble with suckers.