First you need to figure out the ips of public Qizmos that will relay the game. Please refer to the news updates or ask on IRC.
Start up the QW client and type '/connect qizmoip' where qizmoip is the ip adress of the public Qizmo (usually followed by some port). For example, to connect to the Barrysworld proxy (in the UK) you would type '/connect 194.88.93.66:27501'. To bring back the console at any time for entering more commands, use the tilde; the key directly below Escape.
On connecting, you should be greated by the main Qizmo menu. You should be able to navigate around using the arrow keys, if not type, '/say .menu bind' in the console. Other important keys to remember are the Enter key to select a menu option and Backspace to take you to the previous menu. To make the menu appear or disappear at any time, press the Pause/Break key.
Depending on your connection speed, you may find the menu navigation behave a little slugish. There is not much you can do about that except finding a different public Qizmo to which you have a better connection. Try not to get frustrated if you miss the correct menu entry a few times because you pressed the arrows to quickly; it just takes some getting used to.
Find the Client list selection in the menu (fourth on the left) and press Enter.
This will bring up a different type of menu. To navigate this you have to watch the line on top. You will see one word in brackets and brown ([CONTROL] in this case). With the Left and Right arrows you can move between these sub-menus. In some of them you will be able to use the Up and Down arrows to make a selection from a list. Here the [OBSERVE] submenu contains a list of people connected to the same public Qizmo as you are. Using the Up and Down arrows, find the player (or the camera) you are interested in and press Enter. You will get the view this player has on the server and you can sit back and enjoy the game...
Be careful not to use the [FOLLOW] submenu which looks exactly the same as the [OBSERVE] one. Selecting a player here would connect you to the same server he is on as a participant, which in general is a bit anoying.
Remember, if you get lost in the menus just press Backspace a few times and you should end up back in the main menu. In the worst case you can start from scratch by connecting to the Qizmo again.
Maybe you will find that the teams don't have their colors set properly, e.g. all players have different colors or there is even a red player in both teams. In a case like this, use the 'team xyz' console command, where xyz is a name of a team in the game. To force colors on the players, type '/say .color 13/13 4/4' in the console. This will make one team blue (the team you selected) and the other red.
To make the difference between teams even clearer you can use the fullbright skins. Type '/say .skins friend nmy' in the console. The team you selected will now be bright white whereas the enemies will show up red.