Some posts _ pages of the www.teamcoaching.imservers.nl

Some posts _ pages of the http://www.teamcoaching.imservers.nl site are rather long example:
http://teamcoaching.imservers.nl/teamcoaching/

I need to split posts and pages into sections, where at the end of a virtual section in the display there is a message "more..." or "continue...." (preferably translatable)

I notice a "more" function in the editing screen but cannot get that to work.

Can you please assist? Tx - Erik W.