If you have the luxury of unlimited funds and an equal amount of storage space, it's very easy to stock a bar - go to your favorite liquor store and get one of every kind of spirit and liqueur they have. Done! Most people, though, don't have this kind of budget, so the question remains, "What do I really need to stock my bar at home - hopefully without having to sell the children?"
The Basics
A good place to start is to take a look at your own favorite three or four cocktails. What do you order when you go out for drinks? Find out what's in it, and how to make it. You can look for recipes on line or in a recipe book, or even better, talk to the bartender that makes the one you like. Most cocktails have many variations, so if you're going to make your own, you might as well make the one you like best.
If you can't resist a martini, then you'll need vodka. Live for margaritas? Put tequila on the list. If the evening isn't complete without a pina colada, rum is a must. If you're starting small, it's only practical to make sure that you have the ingredients to make the cocktails you enjoy the most.
If you're thinking in terms of entertaining, you'll want to be prepared with the most commonly requested liquors. Your shopping list should include a 750ml bottle of rum, vodka, gin, tequila, and whiskey, as well as a bottle of red wine and one of white wine, along with beer. Add a bottle of coffee liqueur or Irish cream, and you've got a great starter bar.
Now it's time to build on the basics. Again, if you are only buying a bottle here and there, let your personal cocktail choices be your guide. If you enjoy martinis, add flavored vodkas - citron, vanilla, berry, orange, and pepper are popular choices, although the options seem to be endless. If you serve a lot of whiskey drinkers, branch out to include Canadian whiskey, Irish whiskey, bourbon, or Scotch. Brandy or cognac are popular after-dinner drinks.
Vermouth is experiencing a resurgence in cocktails, both the sweet and the dry varieties. Many liqueurs are used in cocktails as well as aperitifs (drinks served before dinner and often believed to aid digestion). Start with an orange liqueuer, such as triple sec or cointreau. Other commonly used liqueurs are curacao, creme de menthe, melon, chocolate and amaretto, as well as flavored schnapps such peach or raspberry.
In general, unless you have a brand preference, choose medium to premium brands. You'll spend a little more to start, but in the long run you'll be happier with the results. Some people insist that there are brands that are "too good to mix," but there's no such thing. Instead, ask yourself why would you want to spend your hard-earned money on a liquor that has to be drowned in a mixer to be drinkable? Buy the best you can afford.
Now that you've set up your home bar and decided on your liquor, select the right glassware and pick your mixers, garnishes, and gadgets.