Okey dokey. Help me out here because I've yet to PvP in this game. I press the button, I let the timer count down and spawn...somwhere? Then what? What happens next?
Click the faction symbol beside minimap > PvP queue menu
Click "Queue Solo" ("Queue as Group"" if you are in a group with up to four friends who want to join the same warzone together).
You are now in the warzone queue, and the faction symbol you clicked should be pulsing.
After a (hopefully short) period your warzone will pop, and you will have c.1min 20s to click on the join warzone button.
You will now find yourself in a closed warzone instance. There are four maps: Alderaan Civil War, Novare Coast, Voidstar and The Pit (Huttball). Each has a different victory requirement, described as you enter.
Pretty simple and you've probably already worked it out. Have fun.