I do recommend SOME limited note-taking on RC passages, although not so much on CR. However, remember that the answers often don't reference specific details and, if they do, you're going to want to reread that part of the passage again, anyway. Thus, don't take any notes on specifics, but rather simply on the overall structure, something like a map. Here's an example of what a map could look like:
Para.1: Introduces topic -- bees mating habits -- anomalous
Para.2: One explanation for why -- "environmental" explanation
Para.3: Another explanation -- better -- "genetic" explanation
This keeps you focused on what's important, gives two big headlines to the major theories proposed in the passage (it's always a good idea to have these headlines, where you name the major theories/models given, so that you can quickly identify which one a given detail question is talking about and focus your rereading accordingly), and lets you think geographically on later questions: that is, you can see "where" information is in the passage before you worry too much about "what" it is.
However, any more notes than this are superfluous and will hurt your timing. Another great feature of taking really really simple notes while reading is that you'll end up asking yourself, as you read, "What's important enough to write down?" This is great because it is EXACTLY that question that will keep you reading actively and aggressively looking for the author's Main Idea as you go. In fact, I think this is the greatest benefit of economical note-taking: it forces you to actively attack the passage and look for the important parts. Even if you never look at your notes, if you learn to make a great map of the passage, you'll end up having read it more cleanly.
That being said: be careful of LSAT passages. They are significantly longer and more detailed, with harder questions, than GMAT passages, and are in this sense poor practice. They also often have as many as 7 questions per passage, which is twice what you'll see for a GMAT RC passage, and thus reward a bigger time investment in reading the passage itself (more time spent closely reading = more points in questions answered correctly; on the GMAT, it's just the opposite, since if you only get 3 questions and 2 of them are Global questions, what was the point of reading any of the details so carefully?)
Hope that helps!