Zotero works well in both Chrome and Firefox.
(In the past, the Firefox interface was different, but at this point it works essentially the same way in both browsers.)
What Zotero does
Zotero is free software based in your web browser that makes it easy and efficient to keep track of citations and other sources you’ll use for your research – making your research portable – and also makes it easy to build bibliographies. It works in both Firefox and Chrome.
Go to zotero.org and click the big red “Download Now” button. A new page will load.
If you’re using Firefox, click the button on the right – “Install Firefox Connector.” If you’re using Chrome, click the one on the right that says “Install Chrome Connector.”
(if you’re using Chrome) You’ll be taken to the Chrome web store, where you can install Zotero as an extension.
|(if you're using Firefox) At the popup warning message, click "Allow." Click "Install Now" in the next box, and Zotero will download. Click on "Restart Now" and your browser will restart.
Now that you've added Zotero to your browser, go back to zotero.org and click “Register” in the upper right-hand corner to create your account. Fill out that page with the information it asks for, and then open the link in your email to confirm your account.
From this point on, the basic principle behind Zotero is that you'll click a button in your browser to save a citation to your Zotero account.