What are some healthy vegetables which can become the ingredients of my recipes for salads?

I am on dieting and my nutritionist has told me to eat as much salad as I can. I have never made any salad and don’t have any idea about it also I want to know which are the best vegetables that I can use in my recipes for salads. I want to make the salad healthy and full of nutrition. So I want to know what are the vegetables that I can add to give my salad color, taste and nutrition. Do you think adding broccoli is a good option.