The area itself is fairly small, with an ideal exit level set around 6 or 7. Of course, your character can leave earlier or later depending on personal preference. There are some who have managed to leave at level 1, and others who have spent many months grinding to level 20 on low-level mobs just to get the prestigious "Legendary Defender of Ascalon" title. This title is entirely too complicated to explain in this article, but some research on what is known as death-leveling will help you appreciate this jaw-dropping feat.
When you first arrive in Pre-Searing, you start in Ascalon City: the main hub of the five available towns and outposts. This is where you can linger for awhile, gaining quests that relate to the area, learning how to use the merchant, how to join others in a group and so on. This city is quite large in comparison to others in Pre-Searing, with three levels of stairs and a wide array of quest chains to keep you entertained and educated for awhile.
One of the best aspects of Pre-Searing is the fact that you have a limited amount of skills available to you, and a limited maximum armor type that can only be obtained through collector NPCs. These collector NPCs offer a variety of pieces with improved armor rating depending on the class, but it's important to note that there is no NPC for headgear armor in Pre-Searing. This is something ArenaNet removed from the game, so you're stuck with the headgear you received when you created your character.
An extremely popular NPC and future icon of Pre-Searing is the small child known as Gwen who resides just outside the gates of Ascalon city. Gwen is the first real example we have of an NPC who can join you, although she is not considered an actual party member, nor is she considered a henchman (there are no henchmen in Pre-Searing). Ironically, because of her iconic status in the game, ArenaNet brought her back as a grown teenager in the Eye of the North expansion.
Once you get to the point where you feel comfortable with most of the enemies you've encountered in Pre-Searing, and you've finished most quests available to you, there is an advanced area of this land where most higher-level players go to gain experience and face a genuine challenge. This area is known as "North of the Wall" or simply The Northlands where the Charr reign supreme. This is also the only place where players seeking the Legendary Defender of Ascalon title can gain any experience. Luckily, there is no death penalty in Pre-Searing though, which comes in handy when you'll face these advanced enemies.
Be sure to continue reading about the outposts and landmarks of this area in the Pre-Searing Gallery.