Writable DVDs and CDs are affected by light, so keeping them in the dark and at a constant temperature helps preserve them longer.

Re-writable DVDs and CDs are nigh useless for archiving, because the dyes used are of their very nature volatile. It's okay to use re-writables as a temporary master to make copies from, though.

I prefer to archive on a few external hard drives for safety, that way if one goes, the info is on another. As for indexing, I make sure the directory (sorry, folder!) name is meaningful, and there's a text file with each archive.

Although they are a bit slow, Netgear make an inexpensive housing for two IDE HDDs, which can be set up as a mirror array (what is on one drive is automatically copied to the other). It's the SC101, and is networked as opposed to USB or firewire. All my really important sfuff (the radio programme and my photos) are also stored on one of those with a pair of 300 gig drives installed... but it's nearly full now!

Despite what people have said above, I think keeping a set of MP3 archives in addition to other backups is valid, as they take up less room than WAVs... it's better to have MP3s than nowt!

As many have already mentioned, I never edit the original, only a copy. The same applies to photographs. It's also worth keeping different 'edits' so you can judge them in the cold light of day... somehow we can hear things differently whilst we're working on them, and think 'Why did I do that?!' afterwards!

It's worth noting that a good (archive) recording ought to be made 'flat' - with no EQ or effects. You can always add stuff afterwards, but you can't take it out!

As for scratch removal, I find the 'pencil' tool in Sound Forge works well, because you can 'draw' the wave form (with experience!), which means you are not only reducing the level, but you can take out the hard edges.

Quite often you will find a scratch on vinyl affects the left channel far more than the right, which is mainly down to the ballistics of the tone arm. But this affects how you deal with the scratch.

Another point when editing - the 'peaks and troughs' of the waveform matter a lot. If you don't take your edit points from 'null' to 'null', you can introduce scratch-like noise because there are hard edges where you've cut and paste. I mark the section, then look at each end and magnify so I can adjust the markers ever so slightly. More difficult on a stereo recording, of course, but rarely impossible.