To make additional, static pages, you can always copy your index.php file, replace the content with the static content for your new page, and save it with the new name. That would allow you to keep all the style, all the sidebar stuff, style-switcher, but have additional pages.
Create file: about.php
Copy code from index.php to about.php
Remove the code in about.php that displays the blog entries.
Put your 'about' content in the section where you removed the blog entries code.
Save file: about.php
You now have an 'about' page that fits in with the rest of your site. Last step is to add a link in your sidebar to the new page.
If you're going to use multiple pages and will have the same sidebar in every page, I recommend creating a new file "sidebar.php" to put all your sidebar content in. Then, remove the sidebar content from your pages and use a php include to include the sidebar.php page. That way, when you need to update your sidebar, you only have to update one file instead of every file.
You can do the same thing with the pieces of the head that are used on all pages. Or, if you want to get really tricky, you can put everything except the main content into two include files (one for the header and one for the footer). Then, your individual page files would only have 2 included and the content for that page.