The personal story in GW2 is a very important part of the game. The way you respond to certain characters within the game directs how your own story within GW2 will progress and be truly YOUR story since no one responds the same way. So it is best to start planning now so when the game launches you can quickly respond since you have already look at these question ahead of time and written down your responses to them.
But first there is the beginning. As you make your character when you first launch the game and after you have decided what your character will look like. You will be ask a group of questions. (for full details please refer to the official GW2 wiki --http://wiki.guildwars2.com/wiki/Biography).
First you will be asked three questions about your profession. For example for the warrior. Will you or will you not wear a helmet and if you do will it be a cap or a full helm. The one profession with the most diversity will be the rangers. They will be asked which of three pets you want to start out with, but each race will have three animals the other race may not have. Example the Sylvari could chose to have a Fern Mastiff, which as you may guess is a plant doggy.
You will be asked three personality questions. They are, will you be a charmer, have dignity or be ferocious.
Next are ten to twelve race related question. Each race having different question to get answers for.
Once this is done and you have named your character you will get your own personalized opening cinematic and your personal story begins. As you progress through the game time to time you will run into or be asked during your personal story cut scenes some questions that will relate to Charm, Dignity and Ferocity. You can choose which ever answer you want to. This will in turn guide your personal story down a path. The game keeps track of the 100 most recent responses and plans your personal story accordingly.