 It's easy to take notes on your sources using Zotero. Select a source from your library or collection, and then over on the right-hand window, choose the Notes tab. Select Add, and you'll be able to start typing. Another way to do this is by selecting your source and hitting the yellow sticky icon above the library. Here you can add a new standalone note or a child note. A standalone note isn't related to any one source. A child note goes under the source you selected, and then again, over in the right-hand window, you can type up your notes. You might note where in your research project you think the source will be most useful, or you might talk about what the source doesn't address, or you might just remind yourself what it's about in general. When you're finished making the note, you see it becomes a sub-item below your source, and you can make more than one note for each source. To remove it, simply select it, right-click, and move the item to trash.