Question is pretty simple, I think.
How can I find out what the page GUID for a certain page in my Composite C1 website is?
I need it for RSS reading from a Blog within the CMS.
you can edit \Composite\content\forms\Administrative\EditPage.xml and add:
so you will see page id during the editing.
The simplest way to get the ID of a page is to create a link to it (in the Visual Editor or a code editor) and then either switch to code view or view link properties. There you will see the GUID.