100 minutes to figure out how to start prepping for the GMAT is a bit much! Until you actually start your prep, you won't process a lot of what you're reading...you won't relate to it. There's great info there, but honestly, you just need to get a good review book and dig in, then start doing practice questions and tests.
I started with a book called Cracking the GMAT...it described everything on the test and included strategies for each question type, along with some practice questions. The book comes with 4 practice tests (now on DVD apparently). It also reviews all the math forumulas and grammar rules you need to know. This is a great book to start with.
I would suggest the following approach: go through each section of the Cracking book (or whatever review book you buy, although the two main ones are from Princeton Review (the one I mentioned) and Kaplan, which is not known for having good verbal strategies), one at a time with the Official Guide at your disposal. The OG (11th edition is the most recent) has over 1,000 practice questions, grouped by question type and getting harder as you go. Do a dozen or so of each section after reviewing the strategies for each section. Get a feel for them.
If you're doing fairly well on those initial practice questions, take a practice test (I don't recommend the paper tests to guage your score as they're not on the computer like the real GMAT), either GMATPrep (download free from mba.com) or the Princeton Review tests (don't use Kaplan either to guage your score -- way off from what most people say).
Compare the results of that test to your results on the dozen or so practice questions you did, question type by question type, and see if your strong and weak areas match. If so, you've got a good idea of where to put more emphasis in your practice. If not, just keep going through the OG, doing several questions from one question type at a time until you're getting the hang of it. If you spend weeknights/days doing practice questions, and do one full practice test each weekend, you'll be able to adapt as you go. You don't want to blow through all the good tests early on, so I don't recommend taking a practice test cold (i.e. with no prep or review at all), so that you don't waste it.
If you're struggling, be sure to keep an error log. Track what you're doing wrong and it will be easier to figure out. If it's not happening, look at taking a prep course (esp if you need overall help) or getting a private tutor.
Hope this helps. A lot shorter than 100 minutes.
