Because you can't pick up free agents, it's best to have at least two quarterbacks if not three on your roster. Hence the typical waiting-on-quarterbacks can be disastrous. When to take any skill position depends on your league scoring system and how your managers within your league typically draft. A good rule-of-thumb is to not fall behind the average rate of the league when drafting quarterbacks. Managers will start doubling up, i.e. taking their second quarterback earlier than in normal drafts. So, if say 80% of the league already have their first quarterback and you don't, this may be a prime time to take your first quarter. Follow this strategy when acquiring your second and third quarterbacks. I personally like to take my second quarterback earlier than most so I don't get caught up befind a run and end up with a weak QB2.