Create ISO Images from CD/DVD and Folder Files

Turn a CD/DVD into an .iso

$ sudo umount /dev/cdrom
$ dd if=/dev/cdrom of=file.iso bs=1024

Turn a folder into an .iso

$ mkisofs -r -o file.iso /location_of_folder/

Generate an MD5 checksum file

$ md5sum file.iso > file.iso.md5

Check MD5 checksum of file

$ md5sum -c file.iso.md5