I have been using Diigo recently. Here is an updated list of my resources that I've been using for my current course. I've also been using it for some work references as well. The list may be searched using tags or keywords which appear on the left side of the website. See them here: https://www.diigo.com/user/k_m_manning
Since I began my studies at Athabasca, and on the recommendation of a colleague, I have been using a software called PERRLA to write and edit my papers and assignments. The software helps to format in APA style keeps a running database of references. As many of my assignments and courses build on each other, I find it a handy way to keep to hand some great resources and papers that are already in APA format. My list is way too long to share, but here is a snapshot of the reference database so you can get an idea how it looks and works. I would highly recommend it to any student new to writing in APA style. www.perrla.com
