Mendeley

You can easily add documents saved on your computer to your Mendeley Reference Manager Library. Mendeley can often capture bibliographic information from these saved documents.

To add a file to your library, click the "add new" button on the left column, then choose "File(s) from computer" to add your PDF.

You can also import your existing bibliographic items/libraries from EndNote^TM and other reference management software.

See: Mendeley, EndNote and Other Reference Managers