Sitecake is php CMS. Also it's a flat file CMS so you do not need a database. All you need is:
Add sc-content class to divs you want editable.
<h1>Fine looking heading</h1>
Do not nest sc-content divs. It's not supported.
If you want same content repeated on several pages, for sidebars, footers or anything else, just name sc-content class with specific name: sc-content-footer.
Upload your website and Sitecake to the same folder on your hosting. You should have this folder structure:
Extract archives with cPanel File Manager or use a script like Akeeba Kickstart
Point browser to http://domain.com/sitecake.php and login with admin pass to start editing. That's it! Not very complicated.
If you haven't tried Sitecake demo, try it now, it should give you some editing feel
If have't seen a 2 minute video in which I show basic editing capabilities, watch it now.