Which program in CS4? Photoshop? Illustrator? CS4 is the name of the entire suite, but you work in one of the individual programs.
It sounds like you're ending up with a .pdf, which is read by the acrobat reader, but which is also supported by a lot of the e-book readers out there. It sounds like you want a more standard graphic file like .png or .jpg?
I have limited experience with the Adobe Suite, but I can tell that you probably need to supply more information for anybody to be able to point you in the right direction.