The quickest workflow would be to use a camera, 1:1 macro lens and a light box. If you have the right equipment, it’d be fairly easy to get good results.

Positive film is quite easy to photograph, and the advantage is you can get the right colours just by looking at the film. For negative film, many people use the Negative Lab Pro plugin for Lightroom. This allows you to batch convert negatives into positive images. However, this plugin is not free (unless you crack it :/). There could be other options for processing negative images, though.

The other options are a flatbed scanner, or a device like a Plustek Film scanner. A flatbed can get decent results, but is terribly slow. Dedicated 35mm scanners like the plustek are faster, have better quality and color, however for large batches are still pretty slow. You can only scan one image at a time.