I'm not sure where to find a tutorial, but if you're trying to form links within the body of your text, it's very easy. When you're editing a section, highlight the words you want to be the link. Above the box where you type, you'll see a icon that looks like two links in a chain. Click that and a box will open. In there, type the URL for the webpage you want people to be able to visit. When you're done there, the words will show up in blue (or purple if you've already visited the page). Now you have a link to the other page people can use. To undo a link, highlight the words and then clink on the icon that looks like the chain links are broken.