Since a lot of time may be spent putting in references that your colleagues also use, find out what faculty and other students in your department use. Working together creating the reference database could save everyone some time. If you are in a science department and use LaTeX as a word processor, some form of BibTeX ( http://www.bibtex.org/ ) will likely be convenient.
I would personally go for Zotero. There are great browser extensions to collect references (check out their website) plus they have an API that allows free editors like ours (https://www.sciflow.net) to drag references directly into the text while writing.
I recommend using Zotero, a few months ago I loved Mendeley, however since updating to Mendeley version 1.19, this program began to encrypt your data, so you can not export your information (notes, tags) to another bibliographic reference manager .
On the problem of data encryption, I suggest reviewing:
https://www.zotero.org/support/kb/mendeley_import
Zotero is a free software, unlike Mendeley that was bought by Elsevier. Zotero has a very active community, where supplements are generated every day for the improvement in the administration of its articles.