If you are looking for a 13" laptop, it is likely that size, cost, or both are primary concerns. To find the right 13" laptop for you, you will want to make a list of priorities, and then search for the laptops that best fit that list. As with all laptops, you will also need to decide what software and hardware are right for you.
First of all, you will need to decide if you are looking for a Windows or Mac laptop. Of course, you can always install another operating system, but those two are the most popular by far. Most laptops come with a wide variety of useful hardware such as built in wireless internet, DVD players, and CD/DVD burners. Just make sure that your 13" laptop has the features most important to you. Depending on your other priorities, you may have to make some sacrifices to accommodate the price or weight you want.
Now that you have decided on the basic components of your laptop, you need to decide if price or size is more important to you. Because of their small size, a 13" laptop can sometimes be categorized as "ultra thin" or "ultra light." You usually pay significantly more for the convenience of size and weight. An especially ultra thin and light 13" laptop might be four or five times more expensive than a similar model which is a little heavier and thicker.
Because there tends to be a trade off between size and price, it is good to have in mind how much you are willing to pay, and how small and light you need your laptop to be. One good way to go about finding a price point for your 13" laptop is to decide ahead of time how important size and weight are. If you plan to use your laptop for hiking and business and you will need to carry it frequently and for long periods of time, it might be worth paying more for the added comfort and convenient of a thin, light laptop. On the other hand, if you will only be carrying it to and from work, or between rooms in your home, you might be able to sacrifice a little bit in the size and weight, to get a less expensive model, or to add extra features, a larger hard drive, or more memory.
Once you have figured out the most important features of your 13" laptop, visit some local computer electronic stores and give some a test drive. With the basics figured you, features like keyboard size, screen brightness, and location of external ports can help you pick just the right laptop for you.