I was first introduced to Mendeley by a colleague some 3-4 years ago. Signed up for it, used it a little, and just remembered it again today when discussing with some students, who are in their final academic year, and about to embark on their capstone research project.
If you're looking for a tool to help you "store" the articlesyou found or remember the links you found useful for your research, Mendeley should the tool to consider. If you want to share the articles with another 1-2 individuals, Mendeley allows one private group to be created. Of course, like every other online tool these days, if you want to be able to do more, just pay a monthly or yearly fee and you will be given options to do more. It looks promising. Try it.