Every organization in existence, worth a shit, will have a mission statement and perhaps even organizational goals. These are important to your organization and commmunity but don't spend any significant time trying to memorize them. If you're a competent Jail Guard that works toward being professional in all your interactions with everyone you come in contact with, you'll be helping your department meet thier mission statement and goals.

Your very own Mission statement and goals should be something along the lines of;
Always keep your primary duty of maintaining safety and security of your facility, its staff and clients at the top of your To Do List.
Always work hard to be professional in all your interactions with everyone, bar none.
Work hard to be professional in all your actions while on duty and not.
And always, always, always keep yourself above reproach.
If you keep these few goals as your own personal mission statement you'll be almost guaranteed to have a very succesful career or at least a very personally satisfying one.