Last week I attended the Google Apps For Education Summit in Hanoi. The event featured few tutorials about Google Apps Script. It seems that there is a need for simpler tutorials for teaching Apps Script programming.
Earlier this year I wrote these Google Apps Scripts Web Apps to fetch a RSS feed or web page, parse it and display its content. You can embed these Apps Script as gadgets in your Google Sites pages.
The more technically savvy readers will find the example code helpful in learning user interfaces(UI) development with Html Service and Ui Service. You might also want to read XML parsing with Google App Scripts tutorial as well. Please do refer to latest Google Developer documentation as Apps Script API change over time.
Daily Buzzword Google Apps Script
Google Apps Script to parse and display wordcentral.com's Daily Buzzword RSS feed.
Daily Words Google Apps Script
Google Apps Script to parse and display wordsmith.org A Word A Day RSS Feed
How to add Apps Script Gadget in your web page?
First go to the page you want to add the Apps Script gadget. Select Apps Script item under Insert menu. In the next dialog box, copy and paste the Apps Script Web App URI into the provided textbox and choose select. The Apps Script Gadget will appear in your webpage.