Learn Dutch: Wat is jouw naam? - What is your name?

Yes! Jouw is the emphasized version of "your". You use it when you want to put special stress on the word (like asking "What is your name?" right after someone just told you theirs). In everyday situations, you will very often hear the unstressed version: Wat is je naam?.

Why does jouw end with a 'w'? I've seen jou without a 'w' before.

Jouw (with a w) is a possessive word meaning "your", used here because the name belongs to you. Jou (without a w) is a pronoun meaning "you" when receiving an action (as in Ik zie jou - I see you). They sound exactly the same when spoken, but the 'w' in writing tells you it means "your".

Is this the most common way to ask someone's name in Dutch?

While Wat is jouw naam? is perfectly correct and easy to remember because it matches English exactly, Dutch speakers usually prefer to ask Hoe heet jij? or Hoe heet je? (literally: "How are you called?").