No problem!
(Also, I find it funny that someone upthread has been recommending our challenge problem archive enough that others have been getting annoyed. I actually tell my students to avoid the archive.

At least half of the problems are harder than anything you'd see on the test, and the solutions involve calculations that you'd never be expected to perform on the real test.)
This is what I tell my students in general for the final 2 weeks. (I also give them more specific advice based upon what I know of their strengths and weaknesses, but I don't know yours, so you will have to fill in those blanks.)
Two weeks before: take a practice test (not GMATPrep; something that gives you data on timing, difficulty levels, and your performance). Go through that test to determine your current strengths and weaknesses based upon both accuracy
and timing. DO NOT pay attention ONLY to accuracy. I review student tests all the time and students will tell me "Oh, I'm not so great at X." I'll look at X and discover that the student spent half the time s/he was supposed to on those because the student had spent way too much time on other questions elsewhere in the section - no wonder "X" wasn't so good!
If you use MGMAT tests, here's the data to look for:
First, from the question lists (listing each question you did in each section). Review:
- problems on which you spent >30 sec above or >45sec below what you were supposed to on problems of that type
- problems below your level that you got wrong - eg, if you're currently scoring 650, look for problems in the 500-600 category
Pat yourself on the back for things on which you scored >50% correct (the higher, the better) and for things you answered correctly in the general timeframe you were supposed to spend. For things you answered correctly very quickly, do still pat yourself on the back, but know that doing something too fast increases the chances you'll make a careless mistake - so just be careful.
Second, from the assessment reports:
- areas on which you scored <50% correct
- areas on which you averaged >20sec above or >30 sec below what you were supposed to average
- areas on which there is >30sec (overall question categories) or >45sec (question subcategories) disparity in timing (in either direction) between the ones of that type that you got right and the ones that you got wrong
** Note on some of the average timing data: if your timing got messed up in the section (eg, you spent too much time early on and had to rush later on), then your data will be skewed because you will have been forced to do questions towards the end much faster than you'd otherwise have done them (possibly to the point of making random guesses in a few seconds). If this happened in either section, you'll have to dive down into the data for individual problems rather than use the assessment reports to do the work for you, because the average timing may seem to be okay even though you had a bunch that were too long and a bunch that were too short.
Now, where are you spending too much time and where are you spending not enough? In which sub-categories are you consistently missing things? Why? (Specifically, why did you get wrong anything that you got wrong?) What could you do / change in order to avoid each specific mistake you made the next time you do a similar problem?
Don't forget to prioritize based upon the frequency with which various things appear on the test. If I got that combinatorics question wrong, and I'm two weeks before the test, I don't care - because combinatorics problems aren't that common and my time is better spent on stuff that is more common. The one thing I'll check to make sure is that I didn't go OVER time in getting that one wrong, because I don't want to lose time on this one (or any question on the test!).
Okay, so you've done all of this analysis. Determine:
(a) what your strengths are - question type, content area, etc.
(b) what your weaknesses are - ditto
For weaknesses that are frequently tested, try to get better at those. For weaknesses that are NOT frequently tested,
let them go. Know what they are so you can recognize them when they pop up on the test, know how to make an educated guess, try it, make a guess if necessary, and then move on at or before the expected time limit for that type of question.
One week before:
Before you take your final practice test, develop your Game Plan. Know what your weaknesses are so that you can practice letting them go during your final practice test (as described in previous paragraph). Know what your strengths are so that you can determine when it's worth it to spend a little extra time - eg, you see something that's a total strength for you, but it's also a really hard problem. Here's where you
may want to spend an extra 30 seconds (NOT when there's a really hard problem in your area of weakness!).
Take your final practice test about 1 week before (minimum 5 days before the real test). Implement your Game Plan (as described above). When you're done, review your test from the point of view: did I stick to my Game Plan? How did it work? If I didn't stick to it, when and why did I get off track? How did that hurt me?
Do the strengths / weaknesses analysis again and tweak your Game Plan accordingly (for the big day!). Spend the last week doing high-level review:
- major strategies for the different question types
- major strategies for different quant content areas
- educated guessing strategies for different question types / content areas
- timing / pacing strategies (on individual questions and over the entire section)
- major rules / formulas you need to know (NOT every last little thing; just the most frequently-tested, major stuff)
Don't forget: top performance requires you to let stuff go sometimes. That includes this review you're doing in the final few days - if something is just not working for you and that something is not that common anyway, forget about it!
Day before:
Get everything ready to go: ID, food for the next morning, food and drink for the test center, any medication, anything else you want to bring. Also rip out or photocopy the very first page of easy questions from OG from whatever question type is your biggest strength. Know how to get to the test center. Have a back-up alarm clock. Etc.
That evening, go see a movie or do something else that will occupy your attention without tiring you out. Don't spend the night before studying. You either know it or you don't at this point!
Day of:
Get to the test center 30-45 minutes early. Right before you go in, spend 10 minutes doing some of the very easy questions you ripped out of the OG book. Don't check the solutions (don't even bring the solutions with you). What you're doing now is jogging around the track, stretching your muscles, warming up for the big game. Don't try anything crazy and injure yourself (read: don't do hard questions and/or check the solutions on easy questions and risk killing your confidence).
On the breaks (during the test), have something to eat and drink. Stretch. Do jumping jacks or jog in the hallway. Listen to your iPod (if they'll let you - they may not.) Anything to loosen up, get your blood flowing and spike your energy levels.
Good luck!