I have seen other folks have a couple of sentences in their posts and then it continues on another page. I would like to do this.
In Options/Writing there is a setting that says size of post box: [ ] I have set that to 10 and thought that would do it, but it doesn't. What am I missing?
That just controls your editor size. :-)
One option would be to use Excerpts: This is controlled by your theme so you'd have to do some editing. Relatively simple to change in your theme files. More info at: http://codex.wordpress.org/Template_Tags/the_excerpt
Other option would be to use the <!-- more --> tag when writing your posts. Your editor should have a toolbar button that will insert that automatically for you.
Hopefully, one of those will help you.
Thanks HandySolo, will try that.