GMAT Strategy

I have recently started preparing for GMAT and plan to take it by mid June.

I wanted some advise on what is the best strategy for SC, considering I am not a natice english speaker and am in no hurry for to give the GMAT and can spend all the required time and effort to ace the section.

I bought the Manhattan SC book, after I saw myself struggling with OG SC questions, however I am not sure what is the best way to use the Manhattan book.

After each chapter it provides a list of questions that are in the OG on that topic, but does it make sense for me to do those questions as I am reviewing the study material? Would it not be more helpful if I review all the material first and then attack the questions. The latter would challenge me to figure out what each question is testing, while in the former strategy I obviously know what is being tested and will make the questions look easier????

I am already through half the questions in SC in the OG, should I do the other half following the MSC book chapters or as a test after all the chapters.

Any advise will be much appreciated, I feel SC is the most challenging area and if these are the two important books then using them the right way can make a lot of difference on the outcome.

Thanks,