There is a trick to equipping yourself for the major food-intensive holidays such as Thanksgiving. The Thanksgiving meal is a family meal writ large -- dump-truck quantities of potatoes, a fowl whom you may have children smaller than, more pies than pie plates. The trick is to buy equipment that is up to this particular task, but which you will be able to use again -- or throw away.
Any roasting pan worth its name is not disposable, however. You can buy throwaway roasting pans, but they bend under the weight of the fowl and sometimes can be so flimsy as to be dangerous when it's time to lift the bird from its perch. And they aren't tough enough to stand up to gravy-making at the end.
If you are going to buy a roasting pan, look for one that is about 12-by-16 inches. That will handle the largest turkey and later the largest leg of lamb and even the crowd-sized lasagne. It should have handles that you can really get your fists into, and it should be made of very heavy-gauge aluminum -- at least 1/8-inch thick -- or stainless steel.
A rack is not absolutely necessary, but it will make lifting the bird out of the pan much easier. Try to find an expandable rack, so that you can use it later for roasts or chickens. Lacking a rack, you need two large, stiff spatulas.
An oversized stainless steel bowl for mixing stuffing will be a great relief on Thanksgiving morning. These are usually available in hardware or variety stores for under $10. You want to buy the largest possible bowl if you are cooking an 18- to 20-pound turkey. I use mine occasionally as a chilling bowl -- filled with ice cubes and cold water it makes a nice cold bath for custards or other preparations that need to cool quickly. There is no need to buy an expensive example, however, since quality varies little and matters even less.
A baster is useful for Thanksgiving, but not only in the way you might think. Obviously, you use it for basting the turkey with its own rendered juices. But you can also use it like this: at the end of roasting pour off all the juices from the pan into a large bowl or glass measuring cup. Then let the juices settle for a minute or two; the fat will rise to the top. You then use the baster to draw the good juices from the bottom of the bowl to use in gravy-making and discard the fat that remains.
A long-handled spoon is a good investment and, in fact, unless you're willing to reach into the turkey with your hands, it's the only way to get the stuffing out. Look for the stainless steel spoon sometimes called a basting spoon in professional language. It won't look dazzlingly beautiful at the table, but if the lights are low enough you may be able to pass it off as pewter.
Who hasn't at least witnessed one of those excruciatingly regular arguments over the ceremonial carving of the turkey? This is apt to be the only occasion during the year when the carver notices that the knives aren't sharp. What you need for carving a turkey is a long, relatively flexible-bladed knife whose blade is more or less the same width from handle to tip and from 10 to 12 inches long. Knives called "ham carvers" are usually just fine for turkeys.
And unless you have a brand-new knife, you'll want a sharpening steel. Another option, if you're really in this for the long term, is the Chef's Choice knife sharpener ($60 or $80, depending upon the model), an electrical sharpener that really does work on the dullest blade without ruining it at the same time. It comes in two sizes; buy the smaller unless your knives are really in bad shape.
For those dump-truck quantities of boiled potatoes waiting to be mashed, you need a dump-truck-sized colander. You want the biggest one that will fit into the bottom of your sink, and you want it to have feet to stand on -- not the kind that can only be hooked over the edge of a pot. Finding uses for this later is not a problem -- the first time you cook spaghetti you'll be glad you have it. Your choices will be between metal screening and a solid sheet of perforated metal. The ones made of screen are slightly harder to clean and slightly less sturdy.
If you are really cooking for a crowd you'll probably find your four-burner stove inadequate both in terms of number of burners and their heat output. An extra burner, either gas or electric, will solve this problem. The gas burners are particularly powerful, and come in handy later if you need a really high flame for your wok or giant stock pot.
The one thing on which one person cannot advise another is how to mash potatoes. This is as personal as dreams and hazardous territory for advice-givers. But at Thanksgiving you may be pure'eing more than one vegetable (mashed potatoes are pure'ed) and in large quantities too. Consider a food mill; this homely mechanical appliance not only pure'es but takes seeds and unpleasant strings out of cooked vegetables.
One of my favorite Thanksgiving dishes is a pure'e of potatoes, turnips and leeks. The leeks and turnips can be pure'ed in the food processor (potatoes turn to glue), but leek strings remain. Pure'ed in a food mill, all three can be pure'ed together and the strings are automatically strained out.
For dessert you'll surely have pie. Decorative edges are fairly simple to make on a pie crust if you know what you're doing. Few of us know what we're doing, however. There are decorative crimpers available that do this for you more or less automatically, and will stamp in appealing designs such as hearts, too. At about $1, where could you get art for less?