A good password should be a combination of uppercase and lowercase letters, numbers, and symbols (@, $, &). Ideally, you want it to be as random as possible (kR6@j412LziN).
Also, be sure to use different passwords for each site. If you use the same password on every website, if your password is compromised on one site, it will be compromised on every other site where you used that password.
How do I keep track of my passwords?
At ALSO, we use Keeper to secure all of our passwords.