These are fine for adding photos to web pages and electronic presentations. Spend more money and you can get one of the new Mega pixel models that offer increased resolution. These cameras generate even better images. This can be important if you plan on getting prints made of your image. Another thing to look at is how many images can be stored by the cameras memory and what kind of memory device it is.
Most cameras use a removable memory device of some type.
The images can then be transferred to your computer for processing. You also want to look at how the images are transferred to your computer. Some cameras use the serial or parallel port of your computer. This method of image transfer can be tedious and time consuming. Some cameras allow for connection to your computers USB port either directly to the camera or by using a reader device that connects to your computer.