Dietary Guidelines recommend 2 1/2 cups of veggies per day

for a 2,000 calorie diet, with the following amounts recommended over the course of  week.

Dark green vegetables:  3 cups/week  broccoli, spinach, most greens.

Orange Vegetables:  2 cups/week   carrots, sweet potatoes, pumpkin, winter squash.

Legumes:  3 cups/week  dried beans, chickpeas, tofu

Starchy Vegetables:   3 cups/week   corn, white potatoes, green peas

Other vegetables:  6 1/2 cup/week   tomatoes, cabbage, celery, cucumber, lettuce, onions, peppers, green beans, cauliflower, summer squash, mushrooms.

Dark green veggies- include most of the crucifers (cabbage family); broccoli, Brussels sprouts, bok choy, kale, and collards; it also includes cooking greens such as Swiss chard, and turnip greens, as well as salad green such as arugula, leaf lettuce, and spinach. 

these vegetables are extremely low in calories and fat and contain generous amounts of fiber, vitamin C, beta carotene, iron calcium, folate and vitamin B6.  It is best not to over cook these vegetables.  Dong so causes nutrient loss, and releases the sulfur-containing phytcochemicals that cause their unpleasant aromas.

Orange vegetables get their coloring from carotenoid pigments; beta carotene is the one the body converts into vitamin A.  These vegetables are typically very high in fiber and several of the B vitamins as well as vitamins C and E, and some supply iron and magnesium.

Legumes includes groups of thousands of plants:  a legume has seed pods that split along both sides when ripe, and legumes are classified by whether these pods are edible.  The most common include beans and soybeans, lentils, peanuts, and peas. 

Most legumes area good source of protein and contain B vitamins like folate and riboflavin, vitamin E, complex carbohydrates, soluble and insoluble fiber, and minerals such as iron, calcium,and magnesium.

Starchy vegetables are usually  roots and tubers that serve as nutrient reservoirs for the upper part of the plant.  They are rich in carbohydrates, vitamins, and minerals.  Tubers are enlarged, bulbous roots capable of generating a new plant.  Potatoes are the most common tuber, but Jerusalem artichokes, jicama, and yams are others.

These vegetables can be used to thicken soups, stews, and sauces in place of cream or roux.  Pale and blander vegetables like potatoes or celeriac are more versatile than beets for these applications, unless you are preparing borscht.

Other vegetables  includes crucifers that aren't dark green (such as cauliflower and red cabbage),  foods that are botanically considered fruits (tomatoes, peppers, cucumbers, and summer squash), as well as the extensive families of mushrooms and onions.  These other vegetables vary considerably in nutrients, seasonally, and keeping qualities.