Ares of many of these pages are locked for editing, because it is expected that edits (outside of the editable regions) would be done through the DreamWeaver page templates, so that multiple pages may be updated at once.
If there is a particular page that you want to edit (i.e. areas that are not designated as editable by the template) then you could choose to detach that page from the template by going to:
Dreamweaver Menu > Modify > Templates > Detach from Template
(Pages can be re-attached too).