so apparently the "comparitive reading" where theres 2 passages to read instead of one is a pretty new thing and the older lsats dont have them. how different are these from the other reading passages? and where can you find them? the new sample from lsac as well as the tests at free-lsat.com have comparitive reading questions but other than that i havent really found any.
On the assumption that this is on the up-and-up, you might first look at the basic components of any of the LSAC's materials. Quite honestly, it matters not which you start with. You could even pick one up from 1971 and get a fair sense of essential lawyerish "aptitude" and what it is that law school folk are concerned with. Reading comprehension is obviously a major part of the LSAT, and has been for some time, so the specific form of comparative evaluation is a concern after mastering the basic elements.
You might also read Morten Lund's book on memos. While that might seem premature, it will lend a good sense of the degree of precision needed in all forms of communication. Lawyers are excruciatingly precise, and law school admissions officers are part of this process of defining, observing, and choosing those with a like degree of precision.