If you are studying for the MCAT and applying to medical school, I would be very careful with SDN (student doctor network). Although it can be useful, there is also a lot of misinformation that is spread. Not to mention hearing about how some kid didn’t get in to his dream school with a 40 on the MCAT, 4.0 GPA, and discovering the cure for cancer.
Good luck on your studies! Also, one more thing: I agree with SecularFrummy, but remember – only memorize the basic equations. No need to memorize all the derivatives (e.g. PV=nRT, don’t bother memorizing Boye’s law as well!)