The amount of food you give them depends on the number of worms you have.
If you have 1 lb of worms, I'd try putting 1/2 cup of food in one corner of the bin. Check it after a few days, and if it's gone, feed another 1/2 cup in another corner of the bin.
In order for them to eat quickly, the food must be well on it's way to be decomposing. Chop it into small pieces and put in a container on the counter for a number of days so that it gets soft and squishy for them.
Under-feeding is definitely better than over-feeding. New bins always take a while to get established to the point where they are eating a lot of food.

I'm a first timer also. I don't think I quite got a half pound of worms, got a bucket full (with dirt) from a friend. In any case, it's been two weeks and they are still in there, the bed is moist, but they are all spread out...I put food in once and they didn't eat it.

The bed is full of leaves and apples from the yard. Could it be they won't touch the food until they get through that? Not sure if I should add more food or not.

Don't add any more food till they've eaten what's already in the bin.
Remember, worms don't have teeth, and it takes time for food to decompose to the point where they can suck at it.

If you chop and freeze your food first, then thaw and keep in a container for a day or two to get yummy, they will go through the food faster.

Plus freezing, ensures a steady supply of food when times are lean for the worms, and it creates a place for you to put your scraps instead of throwing it out, till the worms are ready to eat again.

Add a little sand or crushed egg shells. Worms need grit to digest food.

I started a bin for the first time in mid-October and they're just now starting to consume a noticable amount of food.

Yes, they definitely need grit. They don't have teeth to chew their food with. I put between a half cup to a cup of specialized grit that I purchase from a vermicomposting business. I feed my worms once a week, sprinkle the grit on top of their food, and then cover it all with shredded newspaper that I moisten with my watering can. Some people have different feeding schedules. It's all what works for you. I don't like to disturb my worms a lot, so that's why I feed mine once per week. I also don't want it to turn into a chore. This way I don't feel burdened, and am having fun with it. Your bin can even be set up so that your worms will survive for two or three weeks while you are on vacation. I wouldn't leave them any longer than that though, without having someone come in and feed them.

Generally, the worms will eat half their body weight per day, once they get going. That means if you have one pound of worms, they'll eat a half pound of garbage per day. I usually grind some of my scraps, and also have some larger pieces (such as cut up celery or carrots) so that it doesn't pack down and get smelly. If I have a lot of garbage, I freeze it. Freezing helps to break the food cells down, making it easier for them to eat it. You can also shred larger pieces of garbage in your food processer, if you have one. The more broken down the food is, the faster they'll consume it.

They LOVE watermellon rinds, squash, and sweet potatoes. They also love stale flour, cereal, and ground flaxseed, but be careful and don't put too much putting too much flour type products in your bin at once. If you add any, do so very sparingly. I learned the hard way about putting too much in at once, and I ended up with a stinky bin for a week. It did make them fat though, and they made a lot more babies.

When I purchased my Can O worms system, I was told to place a frozen water bottle wrapped in newspaper daily on top of my bedding in the bin through the summer. Even though my bin is inside an air conditioned house, the temperature inside the bin can still get a little warm as the food decomposes. I did this, and my worms were happier and reproduced at a high rate. However, I live in a very warm climate, and keep my house set at about 80 in the summer. The reason I mention this, is if you do make a mistake and your bin gets too warm, stir the contents to fuff it up, add a little more grit, and use the frozen water bottles until the bin is back to normal.

As you can tell, I went through a bit of a learning curve. A well maintained bin will never smell bad. I have already harvested some wonderful compost and my daylillies are going nuts with it. So are my roses and camellias.

There is an excellent book titled "Worms Eat My Garbage". It is written by Mary Applelhof. I think you would enjoy it, and makes a great reference book. It is not expensive, and is available in paperback.

Sandy

I received my worms about a week before I received the bin with no instructions other than add a 1/2 cup of water. I placed the worms in a plastic dish pan 18x9x6 with a hunk of sod I cut up this summer and started adding coffee grounds and paper to the tub. I set up the bin and transferred the contents from the dish pan. Now I am freaked that I have overfed the guys along with all the info on what not to feed them. My questions are how much sugar content, sweet potatoes, from kitchen scraps can I feed them without over heating the bed? Can I feed them moldy olives and stuff from the frig?

Responding to cobar:

If your bin does not stink, you are probably OK. If you think you have overfed them, wait about a week before adding any more food. If the bin is heating up, your worms may be in trouble.

Sugar: OK in small amounts. When in doubt, only feed one end of the bin. If it heats up, the worms have a place to go to escape the heat.

Olives: Probably not, if salt is listed as an ingredient, otherwise, go for it.

Sweet Potatoes: If raw, cut them up or grind them up. If cooked, go for it.

Kitchen scraps, stuff from the fridge: No meat, dairy, oily foods or salty foods. Otherwise, go for it. Most fruit and vegetable waste won't heat up.

Some bins don't like spicy foods or onions or garlic. So far my worms seem to like onion peels. Try them in small amounts and see how it goes. Go easy on grains and citrus.

Grains will heat up. They also get moldy and clump. They will eventually get soft. When they do, the worms will go crazy for them. Add them in small amounts in one small area in the bin.