[RainKindle]

I felt just like you when I started out, and reading about it here didn't satisfy me. I couldn't exactly tell what was what. Now, with a few months of spending time with them, I have a much better idea.
Little miss attitude, Maple, likes to give me a grumpy look when she has to put up with me. I catch her look in tons of photos.
Some of her bad looks are deserved, for example, when she popped out babies, and I took flash pictures of her feeding them when they weren't older than a day. Or when I took several pictures of her for her thanksgiving photo opp. (You can see the best ones in my gallery where she is just chilling and not giving me the dirty look.) She makes the least noise, and tends to be all body language.
Then I have ADD girl, Sugar. If you hold her favorite veggie right under her nose, she will munch, but then soon forget that she is eating her favorite veggie and get distracted and go somewhere else. None of the others have that short of an attention span, especially when it comes to their favorite veggies. She makes this whirring noise when she wants it though. And has the highest pitch when she is hungry, or faking me out for food.
I have smart diabolical Birch. I've handled him since he was a baby, and he runs from being picked up every time. When you walk up to the c&c, you can see him figuring out the way that is the most challenging for me to pick him up. He is smaller than his brother, but is definitely the dominant one. He thinks things out, and knows when to chew on his wooden echoey house, and when not to. He is the one with the best memory. He looked for Maple when I moved her from one area to the now shared cage with Sugar. He looked for Maple in that area for weeks, and even wheeked for her because she was suddenly missing in that corner of the room.
Bonsai, my little chubbers is a good soundmaker for food. Depending on his pitch, intensity, or repitition, I can tell exactly what time of day it is. Even if the mealtime is late, his clock is right on cue to the right time to ask.
Have fun with them, and they will tell you what their noises and actions mean.