POTATO SALAD is about as basic to a summer picnic as pumkin pie is to Thanksgiving dinner. The nostalgia it evokes -- memories of family picnics, hot summer days, swimming holes and chiggers -- probably derives partly from the fact that it's one of the first foods you know you can count on as a child.

Potato salad is reassuring. It's filling, good, and familiar -- the more so because it's relatively cheap to make. True, its often bland, but it needn't be -- and it's a wonderful vehicle for introducing new tastes to your family.

Basically, there are the three kinds of potato salad: the continental (French of German) version, which is basically sliced potatoes in a vinaigrette dressing; the American version (which varies regionally), dressed in mayonnaise; and Russian versions, incorporating both potatoes and a multitude of other ingredients in a sour-cream dressing. The continental potato salad is usually served warm or at room temperature. American and Russia potato salads are refrigerated first, though they generally taste better if they have been allowed to sit out a bit before serving.

The best potatoes for salad are new or waxy russet potatoes, because they hold their shape well after cooking, Idaho and other mealy potatoes should be avoided because they tend to crumble.

To boil potatoes for salad, scrub them, cover unpeeled with cold salted water, bring to a boil and simmer until barely tender -- as little as 12 minutes for the smallest potatoes, as long as 40 for very large ones. Do not overcook the potatoes. They should be firm, not mushy. When they have cooled a bit, they can be peeled or left unpeeled. The nutrients, however, are concentrated in the jackets. What you do with them next may depend largely on what is in the refrigerator.

Continental potato salad is a little closer to the potato field than American salad -- more evocative of sunny fields and herb gardens than of supermarkets and church socials. Before marinating the potatoes in a vinaigrette, French chefs often soak the potatoes briefly in white wine, or wine and broth, then drain them before adding the dressing. This is helpful even if mayonnaise is added later; the potatoes soak up less oil or mayonnaise if they have absorbed other liquids first. If you do add mayonnaise, especially home-made mayonnaise, be sure to keep the salad cool; egg-based foods spoil quickly in warm air.)

Mark Caraluzzi of the American Cafe created the following recipe for a variation on French potato salad. CARALUZZI'S POTATO SALAD (6 to 8 servings) 2 1/4 pounds red wax potatoes 4 ounce white wine 1 1/2 tablespoons wine vinegar 1 tablespoon plus 1 teaspoon Dijon mustard 2 teaspoon salt 1 1/2 teaspoon black pepper 1 1/2 teaspoon thyme 3 tablespoons dill 3 tablespoons chopped parsley 1/4 pound red onion, thinly sliced 8 ounces olive oil 3 hard-cooked eggs, peeled and sliced (optional)

Place potatoes in pot. Cover with cold water to which 1 tablespoon salt has been added. Bring to boil and simmer 12 to 16 minutes, or until tender. Drain in colander and set aside.

While the potatotes are cooking, or beforehand, prepare the salad dressing. In a mixing bowl, place all the remaining ingredients except the onions, olive oil, and hard-cooked eggs. Whisk together about 30 seconds, or until blended. While still whisking, slowly pour in the olive oil until it is incorporated. When the potatoes are just cool enough to handle, cut them into bite-size pieces and drop them in the sauce. Add onions and optional hard-cooked eggs.Serve warm or refrigerate.

Each part of the country has its own ideas about what goes into an American potato salad. In some regions, you don't find much more than potatotes and mayonnaise; in some you'll find eggs, cucumber, celery and onions; in some, sweet pickles, in others, dill. However, few people will be upset by the following basic recipe. AMERICAN POTATO SALAD (6 to 8 servings) 6 to 8 medium potatoes (about 2 pounds) 3 tablespoons wine or cider vinegar 6 tablespoons vegetable or olive oil 1/4 teaspoon dry mustard 1 teaspoon salt Freshly ground pepper 6 scallions, finely minced 1/2 cup or more thinly sliced celery 2 to 4 hard-cooked eggs, chopped or sliced (optional) 3 tablespoons minced parsley 1/2 to 1 cup mayonnaise or enough to bind the salad 1 tablespoon or more Dijon mustard

While the potatoes are boiling in their jackets, prepare a vinaigrette with the vinegar, oil, mustard, salt and pepper, 2 minced scallions and celery. Gently mix the sliced, cooked potatoes in the dressing and chill for 1 to 2 hours. When cold add eggs, remaining scallions, parsley, mayonnaise, and mustard. Add more mustard or vinegar if the salad tastes bland, and salt and pepper to taste.

Garnish with sprigs of parsley or watercress, strips of pimiento, crumbied cooked bacon, anchovies, dill weed, a border of chopped egg yolk, or slices or tomato, bell pepper, hard-cooked eggs or olives.

Adding watercress and grated parmesan makes a simple or store-bought pototo salad surprisingly tasty.

On a hot summer day, few potato salads are more refreshing than this cucumbery number created by Judith Hope of East Hampton and published in "The Potato Book" by Myrna Davis (Morrow, $3.95). SOUR CREAM POTATO SALAD (6 servings) 4 cups boiled, peeled and diced potatoes 1 cup diced cucumber 3 tablespoons minced onion 1 1/2 teaspoons salt 1/2 teaspoon pepper 3 hard-cooked eggs, diced 1 1/2 cups sour cream 1/2 cup mayonnaise 1/4 cup red wine vinegar 2/4 teaspoon celery seed 1 teaspoon prepared mustard

Mix the potatoes, cucumber, onion, salt, pepper and eggs. Set aside. Mix sour cream, mayonnaise, vinegar, celery seed and mustard. Toss with potato-cucumber mixture. Chill until ready to serve.

Salat Oliviere, which is really a fancy chicken salad, is easy to make, pretty and delicious. The chameleon-like quality of potatoes makes them a great budget stretcher. Don't tell your guests there are potatoes in the salad and they may think they're getting an extra-generous portion of chicken. SALAT OLIVIERE (6 to 8 servings) 4 medium new potatoes, boiled and cut into 1/4-inch slices 2 whole chicken breasts, boiled 10 minutes with a chopped onion and cooled 4 small sour or dill pickles, chopped 4 ribs celery, thinly sliced 4 scallions, minced 2 tablespoons capers 2/3 cup or more sour cream 2/3 cup or more mayonnaise Juice of 1 lemon or more to taste 1 teaspoon salt Pepper to taste

For garnish: Several lettuce leaves, 2 hardboiled eggs, a tomato, and 10 olives

Thinly slice the boiled potatoes and chicken and place them in a bowl. Add chopped sour pickles, celery, scallions and capers. Mix equal portions of sour cream and mayonnaise with the juice from half a lemon (more if needed), salt and pepper, and gently mix 3/4 of this dressing with the chicken-potato mixture, taking care not to break up the slices. Arrange the salad in a mound on a bed of lettuce. Spread the remaining dressing on top to give it a finished look, and surrounded it with the egg, tomato wedges and olives.

There's always someone in the crowd who doesn't like anchovies, but a surprising number of people dote on them and the following colorful dish is so satisfying a blend of tastes that it often converts the finicky. Like the Salat Oliviere, this one is elegant enough for a buffet. It's also ideal for the beach. SALAD NICOISE (6 to 8 servings) 8 potatoes, cooked, peeled and sliced 4 eggs, hard-cooked and sliced 1 can achovies 1/2 cup capers 1/2 cup black olives, chopped or sliced 2 tomatoes, diced 2 onions, sliced Vinegar, olive oil, salt, pepper to taste 1 pimiento, sliced Watercress as garnish

In a large serving bowl put a layer of sliced potatoes, a layer of eggs, anchovies, capers, olives, tomatoes and onions. Season with vinegar, olive oil, salt and pepper and repeat layers until finished. Decorate with pimiento and watercress. From "The Potato Book" by Myrna Davis

Nothing makes a picnic table more festive looking that a beet potato salad. Equal parts boiled potatoes and beets (cooked fresh or canned) marinated together in a vinaigrette with minced shallots or onions produce a purple-pink salad attractive enough to overcome prejudice against beets. Other leftover cooked vegetables, meat, fish, or chicken may be added; herring and apples are particularly popular. Garnish with sliced hard-cooked eggs, parsley or watercress, and serve with a green mayonnaise (mayonnaise flavored with a puree of spinach leaves, watercress, parsley, scallions and tarragon).

The Germans often prepare a hot potatoe salad with bacon. For 6 potatoes, dice 8 strips of bacon and fry them with a large onion, minced. Add 1/2 cup of vinegar or white wine and 1/2 cup of beef stock to the bacon mixture, plus a pinch of sugar. Bring it to a boil and pour it over the sliced boiled potatoes. Add salt and pepper to taste. Sprinkle with minced parsley. You can also incorporate a little sour cream if you like. This potato salad is equally good in the winter.