Mendeley has a both a desktop client and a web version. Using both together works really well - in the web version, you can easily add citations from any computer, and there is a "suggest" function that will show you similar articles to the one in your Mendeley library. The desktop version is great for editing citations, adding tags, and adding references to your paper-in-progress.
- Getting started: download the desktop version here, when you sign up for an account: mendeley.com
- Add the web importer to your browser. This will make importing citations from library databases and Google Scholar incredibly easy.
- Let's add some articles! You can drag-and-drop pdfs into the Mendeley desktop window. You can even drag entire folders of pdfs, and Mendeley will read the available metadata (info about the source) and let you know if it was successful. If your pdf is just scanned images (jpg, for instance), it's unlikely to find the metadata, but if it's from a database, it nearly always finds the right information.
- You can also add sources using the web importer. Do a search in Scholar.google.com and click the "Save to Mendeley" button in your browser bar. You'll see all the articles on the page in the sidebar. Choose which ones you'd like to add with a single click on the + button, and when you see the green checkmark, it's in!
You can add citations to your paper in progress with a Microsoft Word plugin under the "Tools" menu.
If you use another word-processing application, you can just drag and drop the citation from Mendeley into your Google doc or Pages file for the bibliography. You'll have to manually enter the author-date for in-text citations.