Some basic info can be found on the official Wimbledon site.
The queue is a continuous line starting Sunday at 8am before day 1 of the Championships. It is located in a park a few blocks from the All England Club.
The best way of getting to the Queue is taking the tube to the Southfields stop and walking up Wimbledon park road for about 5 min and the queue will be in a large park on your left. You can't miss it!
You must join the back of the queue which ultimately leads to the ticket office (many, many hours later) where you can purchase tickets for that day’s play. The many Stewards (people who manage the queue) will direct you to the right place. The line is broken up into rows, starting at the right side of the park as you are approaching. When the row is full, a new row is started right next to the prior one.
The most important feature of the queue are the queue cards. This document is basically gold since it holds your place in line and entitles you to buy tickets when that time comes. Do not lose your card! It is also not advised to be missing when they are given out (the stewards will usually hold yours until you show up if your neighbors vouch for you but why take that chance).
Other things to note:
Cash- There is only 1 way to pay for the tickets you have been lining up for hours for. Only British pound sterling cash is accepted so make sure you withdraw more funds than you think you will need from the ATM.
Left luggage- After spending the night in the queue you need to pack up all your stuff. The stewards typically start waking people up at 6am and you can bring everything to the left luggage area (opens at 5:30am) at the front of the queue. You can only bring one bag into the grounds so everything else has to be either brought to left luggage where the fee is £5 per camping equipment item and £1 for other bags. There is a new rule about left luggage and they will only accept bags that are “airline size” of 60cm x 45cm x 25cm. For this reason, if you are planning to camp out and need a lot of stuff I highly suggest finding lodging nearby so you can go back and forth to leave bags.
Toilets- There are 2 sets of toilets located both at the front when you enter the park and also at the far end, across the width of the field. I was pleasantly surprised about the facilities and they are a bit nicer and cleaner than the usual temporary restrooms.
Safety- As woman traveling myself, I felt quite safe sleeping overnight in the queue. There are many stewards walking around all night, not only for safety but also to make sure people are actually sleeping in their tents and not just setting them up to hold a place in line. Definitely not a good idea to take anything too valuable and if you do have electronics or something that may be stolen, you can always ask your queue neighbors to keep an eye on it if you step away from your tent.