Hi,
Do somebody know how to change the name of a Wiki Page?
Situation:
Starting the page by creating the page name I created a name that’s not very cleverly made. It was not exactly covering the content.
Current name: http://wiki.openstreetmap.org/wiki/Overzicht_Verkeersborden (Overview road signs)
Name to be: http://wiki.openstreetmap.org/wiki/Overzicht_Nederlandse_Verkeersborden (Overview Dutch Road Signs)
Can somebody help me?
With the default wiki layout, there’s a “move” menu item hidden behind the arrow directly next to the search field (upper right corner of the page). You need to be logged in.
… and as far as I remember you also have to move the discussion page as well! (Maybe only when there is some content in there and the link to it is NOT red?)
Have a look at the log of page renaming in the wiki → http://wiki.openstreetmap.org/wiki/Special:Log
Afaik this is done automatically when you move the main page, unless you explicitly disable it.
It even says so on when you click “move”:
"The associated talk page will be automatically moved along with it unless:
Lok at it … A wiki specialist.
The page I create will cover different other pages that must revoved later on.
Is there also a trick to do that job?
The trick to is to become a wiki sysop. 
Normal users cannot delete wiki pages. But they can use the {{Delete|…}} template on the page to let the sysops know that the page is no longer needed.
Alternatively, you might consider replacing the content of the obsolete pages with a redirect to the new page.