1. Add directly from the Mendeley Research Catalogue
The Mendeley research catalog is now one of the world’s largest open databases of research, with nearly 80 million papers indexed. You could find the paper you’re looking for on Mendeley and add it to your library with one click.
2. Export directly from online databases such as ScienceDirect, Scopus.
3. While browsing web pages
Install the Web Importer bookmarklet to save references to your library directly from the page of the database you’re browsing. This is one of the easiest ways to add documents. Click the toolbar button as you come across a paper you’d like to save. Supporting 47 common research databases and repositories, the bookmarklet also works on any page which contains the reference information embedded in COinS format.
4. Drag & Drop
If you have a collection of PDFs that you’d like to add to Mendeley, you could add them to the watch folder as described above, or simply drag and drop them onto the open Mendeley window. Easy access to recently added files is provided by the “Recently Added” folder.
5. Use information exported from another program
XML, RIS, and BibTeX are common formats used to export reference information. Mendeley can import these formats and some others, so wherever you’re getting your reference lists from, Mendeley can handle it. If you have the choice (i.e., you’re exporting from local software) BibTeX and XML are the preferred choices to make sure all the information you may have added to the reference in the other program transfers accurately.
6. Manually
You have the option to complete a record manually if you cannot import it.
Acknowledgement:
http://blog.mendeley.com/tipstricks/7-ways-to-add-documents-to-mendeley/
After you have imported your PDFs you are able to view and annotate them in Mendeley Desktop. You can add notes and highlight text. Read more here:
http://www.mendeley.com/features/read-and-annotate/
