Hi NickyK
I've checked out the link from emaol, which is excellent. Have you read it yet? It'll tell you what to do (it's got a whole section on copying content from your iPod to your computer, on the left hand side of the page linked to)
Be v v v careful (i.e. do not press erase and synch or all data will be deleted from the iPod), and read all instructions fully before you do anything.
Have you backed up your iTunes library on to an external drive (external storage device)? Might be worthwhile doing in case of any disasters (can get external hard-drive relatively cheaply), and considerably cheaper than a panic attempt to get accidentally deleted material back
Nicola