1) Navigate to an article you are interested in reading or would like to cite. You will notice a small icon that looks like a piece of paper in the upper right hand corner of your browser. Simply click it to import your article's citation and a full text PDF when available.
2) Once you have clicked on the icon you will see a message pop up letting you know that Zotero is downloading your paper and its citation.
3) Check your library to confirm that your citation has downloaded and that everything looks ok.
Simply drag them into your Zotero library and it will extract the relevant metadata to create a reference. You may have to manually fix some categories. However, Zotero is very good at correctly inputting the information especially for newer articles that have been thoroughly and correctly tagged.