Your final statement should be as brief as possible. Two double spaced pages are generally sufficient. Stick to the points requested by each program, and avoid lengthy personal, philosophical discussions. However, do not be afraid to briefly include any personal information that may help establish similarities between you and a program. Many graduate programs rank letters of recommendation as high in importance in terms of admission requirements.
Most schools ask for at least three letters.
It may be in your interest to get a letter of recommendation from a faculty member outside the psychology department. This will show that you can and have done impressive work in areas other than psychology, and will support the idea that you have a well-rounded education. Remember to ask faculty at least a month in advance of your first application deadline. You do not want them to rush your letter, but to have the time to give it some serious thought. Copy of your transcript with courses taken from letter writer circled or highlighted.