I have two 4 month old dachshunds, and I feed them 1 cup in the morning and 1 cup in the evening. I sometimes feed them a slice of apple in the afternoons, not everyday 3 or 4 times a week. Is there anything else in the way of people food that I can use as a treat. I'm not sure what is good for them. Thank You.

You can count on a AAFCO approved dog chow being good for a dog. Veggies except for onions are sort of neutral, adding almost nothing in the way of calories or usable nutrients. Beware of choking. My favorite treats? A little of the dogs regular kibble or ice cubes. My one Lab was sulking at dinner time tonight. I finally realized, I had opened the freezer and not given her an ice cube. The other Lab was outside at the time.

As for how much to feed:

Your dog definitely should be narrower at the waist than the hips and chest.
You should be able to easily feel the ribs, but not see them. Each dog is
Different. Standard recommendations are a good place to start, but each dog
Must have its food adjusted to its individual needs. See
http://www.purina.com/dogs/nutrition.asp?article=292. Overweight is terrible for Dachshunds. Their back gives out.