The Most Important Things
If you are not comfortable with the camera, you are not going to use it. It should feel good in your hands. The viewfinder should be clear and easy to see through. The LCD screen should be visible in sunlight. The camera should be light enough so carrying it will not be a burden. The controls should be easy to learn and use so you won̵7;t fumble around and miss an important photo. All these cameras have an automatic mode that allows you to just point and shoot. As you get more experience, you will be able to use the camera̵7;s settings to exert more control over your pictures.
Kit Lenses
These cameras are all available with one or two lenses, sold as a kit. The kit lenses are generally zoom lenses, with focal lengths ranging from about 18 mm for a wider angle to about 150 mm for bringing distant objects closer. With the zoom range, these lenses will suffice for most situations, so you will not have to carry additional lenses. They produce acceptable photos, but as you gain more experience, you will probably want to purchase lenses that produce higher quality images. You will have to decide on how much equipment you wish to carry.
The Megapixel Myth
The number of megapixels in these cameras is not a determinant of image quality. More megapixels allow you to make bigger enlargements. However, if you don̵7;t intend to make photos larger than say, 16 inches by 20 inches, the number of megapixels is largely irrelevant. All these cameras have at least 10 megapixels, which is sufficient for almost all uses.
Other Considerations
The camera̵7;s burst mode, the number of pictures it can take in one second, is important if you are going to photograph action. Live view, the ability to frame the subject on the rear LCD screen, is a nice feature. You should learn about each camera̵7;s battery life and the type of batteries used. The battery should last for at least a full day̵7;s shooting and be rechargeable in a short time. Many of these cameras can take high-quality movies, which may be an important feature to you. It should be easy to switch between the movie mode and stills.