I was the first to have my profile evaluated on this website, and Sameer did a great job at that! I'm glad to be the first to share my GMAT experience with you guys.
I gave GMAT late December 2011, and scored 760 (Q 50, V 42, AWA 6.0). I was a college senior at that time, and applied to HBS 2+2 in Round 3. Sadly, didn't make the cut. Graduating from a 50 year old IIT this year and joining an investment bank.
Preparing for the test:
GMAT is a very unique test in the sense that different people need very different ways to prepare for the examination. Almost every person who appears for the GMAT has some familiarity with both English and Mathematics, and it really boils down to what your starting point is, how well you understand the test, and how smartly you prepare for it.
In my case, I'd been through the standard engineering-entrance-examination story only three years back (read IIT-JEE, AIEEE, BITSAT), which had ingrained in me enough math to make life much simpler when it came to GMAT. Knowing the Problem Solving part of Quant won't be a problem, my efforts in Quant were focused towards the Data Sufficiency part. Unlike problems like finding the sum of a series, or the angle in a diagram etc, these problems can get really tricky as you get more and more difficult problems, and loads of practice is recommended.
As far as Verbal goes, Sentence Correction is essentially about recognizing patterns. There are a limited number of types of mistakes, and once you understand them and practice a bit, your eyes will automatically start looking at sentences in the right way and catch mistakes right away. Take a book and understand the possible mistakes, then practice, practice and practice. For someone getting back to English grammar after a long time (like me), it might be intimidating to suddenly see words like Adverbs, Prepositions etc once again, but believe me when I say things are pretty simple once you get the hang of them.
Critical Reasoning (CR) and Reading Comprehension (RC): You'll get books with all kinds of strategies, tips and tricks pertaining to both CR and RC. But frankly speaking, I think those will only confuse you. For CR, grab a book and get a feel of the topic, but I won't recommend trying to memorize algorithms
Step 1: Identify the type of problem.
Step 2: If type of problem is X, find this part of the sentence, and that part of the sentence.
Step 3: Is A part implying B? No? Then it's a trap! Strike off this option)
CR is plain logic, nothing more. Practice, and you shall do well. Similar is my opinion on RC. After all, all you need to do is read a paragraph, understand it well, and answer questions. Many books will give you complicated step wise procedures (like the one above), but I don't believe in them. But yes, in RC your speed and accuracy does depend on your level of familiarity with the topic. For example, as someone who's done Science/Technology for a long time, I find Philosophy topics hard to really get, and had to spend more time doing those paragraphs. Practice a lot and practice on a variety of passages.
Note: I gave my test before the new pattern, so I won't talk about the IR section.
Analysis of an Argument: Scoring here is really about understand the kind of analysis GMAT is looking for. The argument is always flawed, and often very clearly so. Search for a guide "Cheeseburned AWA", it has a pretty good structure for this essay. Look at a couple of sample essays, and try to follow the pattern. Introduce the topic, say it is flawed, point out and number the flaws, propose what the author could have done to fix them, etc etc. Put in good connecting words. "Although, because, firstly, in conclusion, while the author is correct in saying that, etc etc". I found somewhere online a set of 200+ essays, reading through them really made me understand what was wanted. If you aren't sure you can write good English, write a couple of essays and ask a friend to check them for grammatical mistakes.
Official Guides (OGs) - Do as many as you can, as many editions you can find. Actual retired questions, what else could you wish for?
Aristotle SC Guide, Manhattan SC Guide
GMAT Critical Reasoning Bible
Comprehensive Critical Reasoning Bible
Did just the OGs here.
- GMATPrep is an absolute must. There are two tests, but they don't have the same questions every time. If you separate them sufficiently (by say a week), you could give each test twice without much overlap. My scores were between 760 and 780. Your scores here will be a very close indicator to your final, actual score.
- MGMAT has a free test online. Scored 750 on that.
- Kaplan GMAT Tests are tough and score badly. I always got around 640-660 or so, but well add a 100 points to get an estimate :P
Time put in:
I put in around 3 weeks, but then I was still in exam-giving and studying mode (as a student), was totally free (it was vacation time), and was very confident in math (thanks JEE!). Around 8-10 hours per day.
Understand what your strengths and weaknesses are, and optimize your study according to that. Give tests regularly and see if you're weak in certain areas. Fix them. GMAT isn't difficult, just work hard and work smart. All the best!