There is a lot of confusion out there as to how to convert your ZIP files like CBR or CBZ to PDF for viewing on your eReader. It's actually pretty simple and that's probably why its so hard!
First off, digital comics are often presented in CBR or CBZ files which you can read on specific reader devices. There are also Apps available that will allow you to read these files without converting them, but I wanted my comics and graphic novels to display on my iPad right next to my "real" books so PDF was where I wanted to go.