The documentation for the webserver and the CMS is bundled with the product. You reach the documents from your insite editor by clicking the Docs tab. Here you can search the docs and view all articles right in your browser.
You can also reach the docs on https://extranet.roxen.com/support/docs/
If you are looking for information about Pike http://pike.lysator.liu.se/ is the place to find it. With tons of examples and complete reference docs you'll surely find something to help you get on the right track with Pike.