Identify birds by sight
I've never considered it a hobby, but more a daily delight of growing up in New England. We had the book in the kitchen and we'd mark off each bird we'd spotted and the date it visited us.
ExpertVillage puts together three great videos on identifying birds by sight. The other series on identifying birds by sound is also helpful.
I've never been a great listener. So, to me, hearing a bird's call seems much more advanced.