In general I study alone, I mean, it’s very hard to study “together” because everybody’s schedule and study modes are so different.
That said, I made plans to study with my friend Xiaopeng every Monday. It’s good to feel that you have some mutual support, and it keeps us going. We usually just go to Starbucks, find a table and do our own thing. I made it through the “bidding process” chapter, I’ll all it a day!
ARE we there yet? 
Candy I love your blog, especially your visualizations. I’m putting together a list of ARE resources as I go through each exam. I just added your site to the list for CDS.
For anyone who might find it helpful to take quizzes to study for the exam, on my page of resources for the CDS exam I have a 25 question quiz that is randomly generated from a pool of over 100 questions. That method of studying has been my favorite so far. http://designerhacks.com/cds/