Main dish? Side dish? Soup and salad? A salad bar can be an attractive way to serve a crowd a great cold entree or side dish with a minimum of help, or it can be an unsafe, boring disaster; it's up to you.
Safety and general set up of the service are discussed in detail in my article Self Service Food Bars and Buffets
Tips for Better Salad and Sandwich Bars, Taco Bars, Potato Bars. This article deals specifically with stocking salad bars.
Your Salad Bar Backbones
Whether you are doing a side dish salad bar, an entree bar, or a themed bar, these items are fundamental:
Baby spinach or mixed greens
Chopped or sliced cucumbers
Grape or cherry tomatoes or drained, diced slices
Chopped broccoli and/or cauliflower
Red or green onions
Chickpeas or kidney beans
Bacon bits or ham, turkey or chicken deli meats, diced
Chopped or sliced hard boiled eggs
Shredded mild cheese (cheddar, jack, colby)
Dressing selection to include one each creamy, balsamic/vinegrette, and Asian-style dressing, one each low cal ranch and low cal or fat-free Italian