Building a climate-controlled room for CD/book storage

Hi all,

I am considering permanently converting my garage into a study where I can store my CDs and books. As Sydney generally has quite high levels of humidity, I would like to implement whatever best practices there are to keep the room as cool and dry as possible.

Can anyone provide some tips on designing a room with an optimal storage climate? Central air-conditioning is probably not an option, although I do have a dehumidifer, so I will be using that.

Thanks,
Brett.