Use things you have already created in your Drive account for your website. If you are going to be creating a Google Website, you definitely need to be using Google Drive. With this option, you can create handouts and presentations using Word and upload them to Google Drive. You can then easily link to these things. You can also design a handout and presentation within Google Drive. Under Google Docs are several options including docs (like Word), slides (like PowerPoint), sheets (Excel), forms (great tool for designing quizzes) and charts. In this case, you have already designed these things. This will allow you to search for what you have designed and use it in your website. In this case, I am going to add a presentation made several years ago which describes websites.