Well the most obvious starting place in any kennel or pet carrier decision relies on the size of your dog. Large breeds of dogs require enough space to move around and play. You need to buy large kennels for them. If your dog is small, you do not need to buy a very large kennel. It will be very expensive and the small pets will feel as though they are out in the open.
Dogs naturally like to climb or even jump on walls. It's part of their genetics. So in the same way that a dog might jump up on a gate to investigate a new noise, they will also try to jump up or even cling to the sides of the kennel. Keep this in mind when looking at kennel sizes as the height of the kennel walls is just as important as the width. If you dog happens to be an avid climber (typically most puppies are), then account for this by getting a slightly higher ceiling than you normally would have.
Believe it or not there are also legal issues that you need to take into account when looking for a new dog kennel. In some states there are laws concerning where you are allowed to place a dog kennel on your property not to mention how you travel with it on the road. These laws primarily have to do with the distance the kennel is placed in accordance with property lines as well as whether or not the kennel is secured properly while in the back of your vehicle, but make sure to check and see what regulations might be in place in your area before making your purchase.
When looking at the various models of dog kennels that are out there, keep in mind the duration of time you plan your pet on staying in there. Some kennels are not meant for 24-hour habitation by dogs. Others are designed for exactly that. It is up to you to know which type of kennel best suits your pet. Each of these kennels is uniquely designed in order to meet the different needs of your pets in every scenario. If your dog will be spending the whole day in the kennel, it must be spacious and very comfortable. There must be room for different exercises. It can be either medium-sized or large. The exact size will be determined by your dog's physique.
A quick little bit on what to do with your kennel once you've made your purchase, dog kennels should be positioned in areas with natural shade if at all possible. If there is no such a place within your property, you should buy only those dog kennels that have a roof. The roof should be of the variety that does not retain a lot of heat on the inside of the kennel. Excessive exposure to the hot sun is not healthy for your pets. You therefore need to pay careful attention to the roofing of the kernel as well as the positioning.