video and music: redundant server storage with cifs/smb access and a front end like Media Portal (i use a windows home server box with about 12 TB on it and Media Portal on a nearly silent media pc connected to my tv via hdmi and my A/V Reciever and to the server via HomePlug networking- and yeah, i know xbmc will run on linux, but i find MP easier to use and keep working and aesthetically pleasing - XBMC is running as a toy on my classic xbox). Just for fun, I have StreamtoMe set up on my server to allow me to watch stuff on the go with my iPad or iPod, but this doesn't really help with the organization part too much.
comics: redundant server storage and ComicRack
Photos: redundant server storage and either Picasa, Adobe Photoshop Elements or Media Portal
and books i keep on my iTunes (ipod and ipad) or Kindle.
Use the stuff that a lot of people have already put a lot of thought into before you try to innovate, at least until you determine that their solutions are inadequate for your needs.
essentially what you need is some kind of fault tolerant network storage and a robust purpose built, database based front-end to handle the organization, access and presentation.
Easy-peasy. The hard part is finding all this stuff, and buying the necessary hardware... Google is your friend here.