There is a single queue at Gate 3, starting in Wimbledon Park, parking lot 10. All tickets are on a first-come first-served basis so if you plan to queue for Show Court tickets, you will need to camp out the night before. If you are just looking for ground passes, you will still need to get there several hours before the grounds open at 9:30 a.m.
Though it sounds like a drag to arrive the night before for tickets, that may or may not be available, the park does everything possible to make sure campers are comfortable. They have installed industrial lighting and toilet facilities around the camping area and even offer catering. You don't have to worry about oversleeping either, as stewards provide everyone with a 6:30 a.m. wake up call.
All of this hospitality has made queuing up an annual tradition for tennis fanatics who look forward to hanging out with friends (and making new ones) while waiting for the main event.
You can find more information about getting tickets for Wimbledon at Wimbledon.com.