Step 1:
Why learn about wine?

Step 2:
How to enjoy wine

Step 3:
What to taste first

The Dos:

• Do start with simple and inexpensive wines, and work your way up to the powerhouse bottles. There is no point in opening an expensive and complex Château Lafite-Rothschild Bordeaux as your first red-wine experience. Start with an $8 Merlot and save the big guns for later. You will appreciate the Château Lafite all the more when you get to it.
• Do try a variety of wines. Trying everything is the only way to build your sensory memory and discover your own tastes. You'll never make any progress with wine if you stick to the same Chardonnay or Cabernet Sauvignon, no matter how much you like them.
• Do go with your instincts. There is no point in suffering through a wine that you really don't like just because you have read that it's supposed to be good. Wine, like art, is subjective. As you become more experienced, your opinions will become more informed, but meanwhile, don't hesitate to voice an opinion about a wine that you're tasting.
• Do realize that the most important characteristic of a good wine is balance. A wine's flavor can have many different elements: fruit, tannin, spice, oak, etc. The best wines have all these things in a complex harmony, and no one flavor overshadows the others. You want your wine to be like a smooth ensemble, not an assemblage of discordant divas, each vying for attention.
• Do use stemware. It may seem snobbish to beginners, but the right glass really does enhance the taste and increase your appreciation of a wine. You need not spend $50 per stem for the finest crystal, but do look for glassware that is delicate, balanced, and has a large bowl, which will allow the wine to "breathe" (interact with the air, thereby releasing all its aromas and flavors). Opt for clear, classic stemware; avoid colored glass or cut crystal (which disguise the appearance of wine).
• Do serve wine at the right temperature. Whites should be cool but not icy; serve them between 43ºF and 53ºF. Pour sparkling wines and Champagnes on the cool side (around 45ºF). Reds should be served at cellar temperature (between 55ºF and 65ºF), not room temperature.
• Do save leftover wine—for up to three days, or perhaps a little longer if it has been corked and refrigerated. Some wines, especially newer reds, can actually improve when they are kept open overnight (because the by-products of fermentation have a chance to disperse). Most wine, however, loses something after the first go-round. You can buy a canister of inert gas specially marketed for spraying into wine bottles, the purpose being to eliminate oxygen contact, which causes wine to oxidize and spoil. Perhaps the best and easiest solution is to use that good leftover wine for cooking.
• Do discuss wine with your friends and colleagues at every opportunity. You might even think about starting a tasting club, where you gather regularly with friends to share new bottles and your thoughts about them.
• Do establish a relationship with a wine merchant. Some supermarkets have well-tended wine departments, but if yours doesn't, then go straight to a reputable wine dealer. Having a personal relationship with a favorite wine merchant who knows your taste and your budget is invaluable. You will get better advice, and the wines in stock will have been selected with more care. Most wine shops take pains to make sure their stock is kept under proper conditions, minimizing your chances of getting a bottle that's been spoiled by improper storage. If you are looking for a specific wine that your wine shop doesn't carry, ask your merchant to order it. As you establish an ongoing relationship with the store, he or she will be happy to special order for you.

The Don'ts:

• Don't think you have to know everything about wine to appreciate or serve it. The best wine professionals readily admit that no matter how much they learn about wine, there is always a lot more to discover. Everyone has to start somewhere. The know-it-all "wine connoisseur" is a bore.
• Don't be put off by wine jargon. In spite of your wine-geek friend Herb, who may toss out terms like "malolactic fermentation" or rattle off endless statistics about "yield per hectare," the bottom line is to decide whether you like what you're tasting.
• Don't pay too much attention to archaic, stuffy rules. The old saw that red wine goes with red meat and white wine with white meat should be taken with a liberal dash of salt. Drink what you like, and again, don't be afraid to experiment in combination with foods.
• Don't think that white wine is only for women, or red only for men. Although certain whites may sometimes be referred to as having feminine qualities, white wine is not a woman's drink any more than red is a man's. Rosés are also appropriate for everyone at certain times (mostly summer lunches).
• Don't store white wine in the refrigerator for weeks. This will cause a loss of flavor and can turn corks moldy. Chill your whites for an hour or two before serving, or use an ice bucket to chill them at the table. As recommended on the list of dos, white wine should be served cool—between 43ºF and 53ºF—not icy cold.
• Don't fill your wineglasses to the brim. A wineglass should be filled approximately one third full. This leaves room for the wine to breathe and provides space in the glass for swirling the wine, which releases aromas and flavors. A wineglass that's too full is also top-heavy and tends to tip over more easily. When you order a bottle of wine in a restaurant, a good waiter will refill your glass periodically (before it becomes empty). If you're taking on the task of refilling the glasses, fill other guests' glasses first, then your own.
• Don't take a wine to a dinner party with the expectation that the host will open and serve it. Few good cooks would go to the trouble of planning a dinner without putting thought into choosing a wine that will be an integral part of the meal. If you bring a wine to dinner, make it understood that it is for later use. It's entirely appropriate to say, "Here's a gift for your cellar," thereby relieving your host of the obligation to pour the bottle immediately.

Text from www.epicurious.com.