Experementing with Various adjunct grains

As we all know, there's bewildering variety when it comes to the grains we use in brewing. First there's the different varieties of barley - 2-row, 6-row, and then the different species; then there's the different levels of roasting said barley - munich, chocolate, patent, crystal, biscuit; then there's other grains we like to throw in - rye, corn, oatmeal, rice, etc..

I'm curious - right now at least - about the effect that the adjunct grains have on the finished beer. So I planned a little experiment where I brew a "standard" amber ale recipe - something that's good, but not overly pronounced; a very "vanilla" beer if you will - then brew several batches using the same recipe and adding a different adjunct grain to each. I plan to try:
Oatmeal (I know, not standard for an amber but I want to keep all else equal)
Rye
Corn
Rice
Un-malted barley
Wheat (as a flavoring adjunct, not a primary grain as in weizens)

MY questions to the rest of you:
1) can you provide any insight as to what each of these adjuncts will add to the beer?
2) Are there any "normal" adjunct grains that I've missed?
3) Do you have any advice as to the conduct of this experiment?

Thanks,
Focus

I should clarify:
- I do extract brewing with specialty / flavoring grains. I'm not a "full-up" AG brewer.
- My "standard" amber is your basic amber DME/LME with crystal steeping grains, cascade/ chinook hops, and White Labs American ale yeast.

The wiki adjuncts page has quite a bit of information, that would be a good place to start.

Edit: I should also mention that most adjuncts seem to require mashing so you would need to add partial mashing to your skill-set if you don't already do those. It's really not difficult though (basically just steeping at a specific temperature), there is lots of great info on the wiki or searching the forum.

I'm not sure if you can steep rye,corn or rice with success. Why not try Victory,Aromatic, Biscuit and several Crystal grains at various weights?