There are a few ways to digitize film negatives. You could scan them in (takes very long), scan the photos they produce in (a bit faster) or you could use a DSLR to take pictures of the negatives. The last method is relatively quick, but requires moderate photo editing skills to correct the colors of the negatives.
It also requires a 35mm film holder. There are some commercial models that attach to camera lenses but its easy to build your own as shown here. This guy was made out of (lasercut) clear acrylic painted over with acrylic paint. It holds a strip of negatives steady and frames a single 35mm negative for capture.