You don't have to get OG2016, no. The SC and CR books come with access to an online list of problems based on question type / content area - 6th edition corresponds to OG2016. If you want to get the OG2015 / OG13 chapter-by-chapter lists, contact our Student Services team at
gmat@manhattanprep.com and they'll be happy to send that to you.
So you're going to need to do some GMAT-level critical reading every day. My two favorite sources are:
http://magazine.uchicago.edu/http://harvardmagazine.com/Look for business and social science topics (and science, for RC). Do you have any friends who are good at real-life reading comp / critical thinking? Read excerpts of articles (eg, the first 3-4 paragraphs), then write up a summary and send to your friend, along with the link to the article. S/he can read it too, then read your summary, and tell you what they think you got right vs. what they interpreted differently. When they come up with something different, make sure to ask them to explain how they know. (I'm just reverting to the plural "they" as the easier pronoun to use.
You won't be able to do this with your friend all the time, but it's a nice way to get some feedback. Mostly, it's just going to take lots of practice.
Also, make your life easier by focusing mostly on Assumption Family questions for CR. Find the Assumption, Strengthen, and Weaken, will likely make up about half of your CRs on the test.
And I do think you can start with some OGs, but start with the lowest-numbered problems in those common areas. If the complicated ones like boldface are driving you crazy, just guess quickly - you'll likely see only one of those on the test. (Basically, all of the other types besides the three listed in the previous paragraph are most likely to show up just once on a test.)
You may also want to download GMATPrep (if you haven't already, from
www.mba.com) and try some of the free CR questions. On average, they're a bit on the lower-difficulty side. You could start there and move to OG after that.
Finally, here are some blog articles that review / dissect CR problems from GMATPrep; the discussion might help you to learn how to work more efficiently on these:
http://www.manhattanprep.com/gmat/blog/ ... reasoning/(That one article links to lots of others.)