The character tracker does not interact with the Guild Wars game, it is only updated by the character's owner. Why update it? You can easily look up where to find each skill your character is missing or impress potential guilds with your PvP ready role-playing characters.
Character screenshots are limited to 500x700 and up to 60,000 bytes in size.
The best screenshots will usually be taken in areas outside of town using the highest visual settings you can get. Use ctrl+prt scr to hide your interface in the screenshot. If your machine can handle it, the best resolution to take the screenshot in is roughly 1600x1200.
Try to get the camera as close as possible without chopping off the feet. To do this zoom out two clicks away from 3rd person mode and tip the camera against the ground until your character's feet is still on screen with a small gap at the bottom. This method works best if there is a slight incline in front of your character.
The screenshot will now need to be cropped and optimized before it can be uploaded. Almost all digital cameras these days come with a software bundle that should be more than adequate for processing the image. When cropping the image, leaving no more than 1/2" of space around your character will give you the most flattering shot and help you to fit within the file size limitations. Save it as a jpeg with roughly 60% quality, smaller if possible without losing any quality.