I usually put out some corn and apples. Smaller apples are easier for them to bite into.
You can buy 40kg bags of corn for about $12 at feed supply stores. Cracked corn is easier for them to chew than whole kernels.
A guy I know buys big sacks of carrots to feed the deer, but I've never actually seen them eating the carrots myself.
One of the guys I deer hunt with told me to try something called "sweet feed". I haven't tried it yet, but you should be able pick it up at the same feed supply stores.
If there's an apple orchard nearby, ask if you can pick up some of the apples that are on the ground. Even when they start rotting, the scent will attract deer. Some places may charge a few dollars for a bushell. I used to get them for free at an orchard 20min. from home. The new owners want $5 a bushell, which is still a good deal. You could also pick a few apples up from wild trees if you know of any in the area.