Good questions. Let's see. Most people study for 10+ weeks, so just FYI, your plan is pretty ambitious. Also, did you take the essays when you took your practice test? If not, your multiple-choice score might be somewhat inflated (since the essays come first and affect your stamina) - just FYI.
So you're looking at maybe a 70 to 100 point improvement goal over 7 weeks - yeah, that's ambitious. You should go for it, but you should also be prepared to take some extra time if you discover towards the end that you need more time. Most people would probably need more than 7 weeks.
It sounds like you're working on your own, so start with this article:
http://www.beatthegmat.com/mba/2010/02/ ... study-planThen, use this article to analyze your practice tests:
http://www.beatthegmat.com/mba/2011/02/ ... sts-part-1(Note: that link is an update to the link that's given in the first article - I updated the "how to analyze your practice test" article about a month ago.)
About th OG, I've done so far 50 questions both in the data sufficiency and problem parts. I find them very easy. Is this normal, or is there some kind of explanation ?
Were they the first 50 questions? The questions are presented in increasing order of difficulty - the higher the number, the harder the question. :)
Finally, you mentioned that you're using some of our books. You can look here for our course syllabus:
http://www.manhattangmat.com/freegmatlearningforum.cfmUnder the highlights section, click on "Official Manhattan GMAT Course Syllabus [pdf]"
Of course, you won't have all of the resources mentioned in the syllabus, but the order of assignments will give you an idea of how to use the books that you do have. Note: you should customize based upon your own strengths and weaknesses. Also, because you want a 700+ score, you are going to have to do a fairly thorough review; you can't afford any big weaknesses at that scoring level.
So get started on the above and come back here to ask questions as you formulate your study plan and analyze your results. If you have questions about your strengths and weaknesses (and what to do about them!), let us know.
Finally, if you are studying on your own, you will benefit from using the forums frequently and well; read this:
http://www.beatthegmat.com/mba/2010/05/ ... the-forumsGood luck - let us know how it goes!