The article below is just a basic introduction to the topic. For something more advanced, written by pros and a fantastic leveling guide, my recommendation would be this Elder Scrolls Online Leveling Guide. I could not find any other guide that comes even close in terms of the impact it had on me.
Bretons are the leading race in the merchant driven, Daggerfall Covenant lead by a Breton himself, High King Emeric.
Bretons possess extraordinary abilities as elven blood runs through their veins allowing Bretons to gain magical powers. They are one of the few races that is human but contains elven descent distinguishing them from normal humans. They are best known as shrewd merchants but that doesn’t mean they are no good in battle; Bretons are brave on the battlefield and they make excellent wizards.
They are nothing but proud people who can be quite quarrelsome at times but through diplomacy, Bretons can easily settle their differences and move forward.
One of the key features of the Breton is valuing prosperity over glory.