First up, Jewelboxing. You buy the software and the materials from them, and then you can print your own cd/dvd covers without the hassles you’ll surely come across if you try to do it alone.
Blurb lets you make your own books. Looks very high quality. I’ll probably be making a few of my own as soon as I get some free time.
Computer Arts magazine has a lot of great resources and ideas. Specifically for packaging, I came across live or die packaging which discusses boxes and templates and design and all sorts of fun things.
I also found a few blogs which are packed full of information, projects, artists, technologies, etc:
