Is there a place where actions like post creation/deletion, page creation/deletion, modification, etc. is saved? Is this stored in the Apache logs?
If this is not saved, is there a way (plugin?) to do this?
There is a plugin called Audit Trail. It will pretty much log all actions for your wordpress backend such as page creation / deletion, post creation / deletion, logging in / logging out.
You can find it here: http://wordpress.org/extend/plugins/audit-trail/
This has also been asked/answered here: System audit plugin?
There three more plugins are mentioned, but I can not post the links to the plugins here because I don't have a reputation good enough :)
Anyway, their names are: