Most digital cameras come with software for communication between computer and camera an interface cable (USB, serial, parallel, or SCSI). This software can download the pictures from the camera to the hard-disk. Some cameras have removable memory-cards, flash-cards, or disk-cards that can be inserted in a PC Card or other reader and then the images are just copied off the card onto the hard disk.
Using a digital camera is a just matter of loading all the desired images from the camera into one directory on your hard-disk. Follow the generic guidelines above regarding rotation and resolution, etc.