3) The bookstore or local library will have tons of stuff on personal statements.
4) I just did a google search on "personal statement dental school" and do you have any idea how many good hits I just got? Great job on doing some of the leg work prior to writing the post!!! Here's a short list from 4 of the first 12 hits.
5) (should be listed as #1) Why not just write your own story about your own life? There has to be something compelling about your life or about you as a candidate. I know it's difficult to write about yourself. Usually it sounds corny (at least mine did to me), but just put it down on paper. As you get feedback from your friends and colleagues, they'll help you focus it to what the ultimate product will be. For now, just put something down on paper.