Other sounds, like those associated with transitions, objects or events are discussed later. Keep in mind that the music must allow your audience to concentrate - I would suggest 'New Age' music. I usually import 'loops' of Indian and New Age music into a new genre of musical track programs like eJay or Magix and create custom background scores. Again, be sure that your scores, loops and compilations are copyright free. Programs like SmartSound simplify things even further - a set of dialog boxes give you a series of choices and create a custom musical score based on your selections.
Event sounds are a genre apart from background scores - activated by clicks, transitions or actions.
It's best to avoid them altogether - unless it is unavoidable or integral to your production. I think it hampers concentration, but then, that's my opinion - not necessarily yours. If your studio can deliver the narration recordings by Audio CD, it would simplify your job further. Just get the different narration segments recorded as separate CD tracks. Video can be classified as of two types.