I have done some research on this and found some of the following combinations work well together when planting vegetables and herbs, or different veggies together:
radishes along with chervil
tomatoes along with basil, parsley, dill, or sage
cucumbers along with lemon balm
lettuce along with corn, carrots, dill
peppers along with marjoram
cabbage along with sage or mint
green peas along with caraway
carrots along with parsley, sage
broccoli along with dill, peppermint, rosemary
eggplant along with thyme
radishes beside pole beans
broccoli beside celery
carrots beside onions
leeks beside cabbage
potatoes beside bush beans
Does any one know of other combinations that work well together?