General Account Settings
You can manage your account in the Account tab found in the top right corner of the site. Click the small arrow to the right of Account and you will see a list of menus. Click Account Settings to get to the screen to manage the following:
User Name (only 3 user name changes allowed)
Password (click the Change Password link under the Password)
Payment Method (if applicable) this is where you add your Payment method information.
Privacy Settings and Notifications:
To change privacy settings go to Settings-->Privacy Settings, located on the top menu on the right. You also change your Notifications tab here to set whether to get email notifications when another member is interacting with you in some way (pm, comment, etc.)
Be sure to save your changes that you make.