Know Which Accessories to Get
If you want a spare battery, you should select one that is specifically made to work with your particular model of notebook. It's not a bad idea to buy the battery right when you purchase the computer--especially if you're buying online, where an extra battery may be offered as an option. Use caution if you buy an aftermarket battery from a manufacturer other than the one that made your laptop: Some of these batteries are priced really well but store less energy. Read user reviews and comments about third-party batteries carefully to make sure you're not sacrificing battery life to save a few bucks.
If you need an external optical drive, don't feel obligated to buy one from the manufacturer of the laptop. External optical drives that connect via USB are generally universal, so look around for a good price.
Among other laptop accessories, consider buying a small, wireless travel mouse. Even the best touchpad can be a nuisance at times, and you can find tons of compact, battery-operated wireless mice that are specifically designed to travel with you and your laptop. If you want to use a laptop mouse on an airplane, however, be aware that wireless versions are forbidden--you'll need a wired model for use in-flight.
You can probably avoid spending cash on a specialized laptop bag or carrying case, which retail stores often mark up quite a lot. Unless you encounter a great deal, or you find a special case made just for the unusually large or small laptop you're buying and you're dying to have it, bide your time. Buying a really great bag is a whole other process in itself--don't get something you're going to hate just because it's expedient and convenient.
If the salesperson tries to push other folderol on you, like screen wipes, blank discs, and extra cables, just say "no thanks." These items almost always carry a high markup in stores, and you're usually better off buying them online if you don't think you need them right away.
When in Doubt, Go Faster
If, after going hands-on with a few laptops, you're just not sure whether you need a faster processor, dedicated graphics, or more RAM, take the leap. Nobody ever complained that their laptop was too fast, but spending the next couple of years working on a laptop that annoys you with its sluggish performance will get old in a hurry. Expect software to become ever more resource-hungry over time, too; the applications you use next year will likely be a little more demanding than what you use today. And if you have an HDTV or you're considering buying one in the future, an HDMI output on your laptop may come in handy.
Consider Whether You Need an Extended Warranty
Most consumer-advocacy groups will tell you not to get an extended warranty; such an arrangement is usually a great profit-maker for the manufacturers and retailers that offer it, and most users don't end up using it. Because they're such good profit generators, salespeople will often give you the hard sell about how you need some sort of laptop protection program or extended warranty.
Be wary. Before you even think about signing up, ask a lot of questions. Ask to see the specifics about what is covered and what isn't in writing--don't simply depend on the word of the salesperson.
Laptops are a little different than most consumer electronics and desktop computers in that they're, well, highly portable. People tend to throw them into bags, toss them around, drop them off tables, leave them to be poked and prodded by kids, and put them on the kitchen table, begging to be victimized by a horrific spill. Know yourself and the environment where you'll use your laptop. If you think you have a high probability of destroying your laptop within a couple of years, you might want to consider the extended warranty. (When we last surveyed readers on their satisfaction with extended warranties, we found that consumers who purchased them were very satisfied.) Also, laptop theft protection plans may be a good idea for college students, who have their laptops lost or stolen with alarming regularity.