I am not sure if my experience may be valuable, as I didn't spend too much time with various study guides, books, questions banks and so on. But still, I'll share.
So, at some point in the beginning of August I suddently understood that the time has come and some proper situation to begin my MBA quest has appeared.
I decided not to waste much time and signed up to sit GMAT in about 1 months after the decision day.
My past experience was that maybe 2 or 3 years ago I downloaded GMAT prep and tried both tests. Scored - if I remember it right - about 660 and 690 then. My maths were fine, although I completely forgot a couple of topics, but my verbal was a disaster. The biggest issue was CR - I could answer only some easiest questions. SC and RC were more or less fine - I never knew much of English grammar (I am Russian), but in past 15 years I watched lots of movies, read lots of books - even without knowing theoretical principles I had a somewhat developed "gutfeel" on what is right and what is wrong.
My preparation scedule was as follows:
Day 1: Read GMATClub forums to understand what study packages / info sources are offered.
Day 2: Bought GMAT Toolkit App
Days 3-4: Solved about 150 random questions to see what my major weaknesses are. My 3 years old impressions on poor CR were reconfirmed.
Days 5-15: Read math theory book in GMAT Toolkit App
, solved about 300-400 questions. Conclusion: weak probabilities and combinations, revising trigonometry might be useful (sin, cos - just basics), a bit of practice with word problems required.
Days 16-17: Googled for these topics, had some practice with questions. Decided that that's enough with maths.
Days 18-24: Bought a $9.99 CR book from MGMAT via GMAT Toolkit. Read it in one day and it really helped. Had some practice solving about 100-200 questions on CR. Structuring arguments as described in the book really helps, although I used only my imagination and didn't rewrite questions on paper.
Days: 25-30: Just removed all filters on GMAT Toolkit QBank and started solving all questions randomly. Or not maybe really solving - I opened a question and if it was hard enough I tried. If I saw that I solved this question before or it just seemed too easy or if the question was on some of my strong topics, I just missed it. This technique helped me to revise about 1000 questions in five days, spending 2-4 hours per day, including 2 hours of commuting time.
The last evening before the actual test I tried GMATPrep test and got 710. My goal was 720-740, so it was fine. The reason to take the test was more about getting familiar with the program and somewhat mentally summarizing my preparation.
On actual test I did an essay, IR and Q in a row without breaks as I felt more or less fine and relaxed. Q seemed me easier than I expected, although I randomly guessed one question in a middle after understanding that I will spend too much time to figure out how to solve it.
Then I took a break, just walked around a bit. Then V - more difficult than I thought.
Actually, as for difficulty of questions and time spent both sections were more or less similar. Gradually harder questions, more and more time required. The distribution of time spent was similar. First, about 10 questions in 30 seconds per question, then about 15 in 1 minute per question. The rest took pretty much all the time left. When I finished Q, I had about 2:30 left on timer. When I finished V, I had about 25 seconds. Most time I spent per question - about 6-8 minutes, twice both in Q and V. This may seem a lot, but it was fine for really difficult ones and considering that easy questions were done without spending excessive time.
Overall, the result was 50, 41, 740 - just fine, I guess. I wouldn't spend more time to get higher score, but I would probably be disappointed if I had more than 20 points less.
So, total time spent = 1 month, 2-3 hours per day.
Total money spent = $25 GMAT Toolkit, $10 a MGMAT CR
book... was there anything else...? Probably not, at least I don't remember.
Key for success: Not going into much details and thoughts - just idetified weak areas and paid attention to improve them. Basic strategy that worked for me on every exam in my life: first study areas where you can get lots of point without much effort, than move to harder ones. Your incremental return on time invested should be highest in first days and close to zero in last days.