This question is probably going to make me look like the biggest nOOb, but I am having a difficult time telling apart these 3 races from the screenshots I have seen. I want to play an Imperial Thief that has loyalty to his own race (will not pickpocket them without cause). I know that Bretons are slightly more pale. That is all I have noticed.
How do you tell the difference?

Well nords are usually bigger and blonder, kinda like Scandinavian people.

Bretons are supposedly based of French normans, brown hair, a little smaller and paler. They are the human magic users.

Imperials are based more off Roman, Greek, Italian Mediterranean cultures.

Thanks! Am hoping once I play with the character creation race will be more obvious.

Nords have the best looking ladies...

We sure do.