ISO Recorder is a free software that allows you to create ISO 9660 images from an existing CD-ROM or DVD-ROM. You can also master them from a file directory on-disk.
The software is mainly useful for converting data to ISO images, then writing them to a blank or rewritable disk, or to media. This makes the files less vulnerable to hackings or virus attacks.
The software is able to access your disk's content via its interface and handle all types of files that are present. All you'll need to do for a given file to be included in the process is to select it, and you even have a multiple selection feature to make this easier.