A digital camera is the easiest way. They use no film. Pictures are captured in digital form and stored in the camera. They are then transferred to a computer. Some cameras make the transfer by a special cable or adapter.
Some cameras produce a floppy disk or a compact disk.
Adequate digital cameras cost several hundred dollars, the best cost thousands. A second method is to use a conventional camera to get prints and then scan the prints with a computer scanner. The least expensive method, if you already have a film camera, is to rely on a photofinisher to convert prints to digital pictures. Many small one-hour photofinishers have the equipment. The pictures will be of a higher quality than those that any but the most expensive digital cameras can produce.