I read in one of the download threads, someone mentioned CD is designed for 25 year of life. Even more than ten years ago, I've heard the comments like: A CD won't last forever. The chemicals within the booklet will gradually react with the disc and eventually degenerate or degrade the quality of the optical side. I was sort of believing this theory and pulled out all the booklets from CDs and store them separately.

My questions:
1. Does CD really have a shelf life?
2. Will separating booklet really help? or Do I worry too much?

Although the idea of a 'shelf life' for CDs is mostly hearsay, optical storage of all types is plagued by a phenomenon known as 'disc rot', where chemical reactions in the materials used to manufacture the discs causes the discs to degrade over time, leading to possible data errors. This problem tends to plague recordable/rewritable CDs/DVDs especially, but some official CDs (especially certain very early CD releases) are starting to show evidence of disc rot too.

Really, if stored and maintained properly, officially pressed CDs should last for quite a long time without evidence of disc rot or playback errors. That means keeping your CDs clear of marks or dust, and storing them in a place free of dust and humidity.

The Wikipedia article on the subject explains this in more detail: Disc rot - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Disc_rot)

The file format you are storing the media in will be obsolete and unreadable on most computers long before the disc itself physically decays.
Accept that at some point you are going to have to converts your files into a new file format and storage media.
Talk to people with VHS. Or Beta. Or laserdiscs. Or cassettes. Or 8-track. Or reel to reel. Or 78's. Or wire recorders. Or wax cylinders.
"This is gonna replace CD's soon; guess I'll have to buy the White Album again..." Agent Kay, Men In Black
JonC

i'd be sure to rip/scan everything in high quality lossless formats, keep a couple copies around, and then even if the disc does decay, it shouldnt affect things too much - you still can play the music, and have the prettiness of the disc

most disc rot only affects things when you try to copy them. there are a number of dvd movies that were mastered badly with errors, or stories of people having a bad burn or bad disc, and it will play fine in their dvd player, but not be copyable by things like windows explorer. the error/rot on a small scale just appears as static or a visual glitch when played.