For any future MBA applicants reading this, here is a list of links that I found useful during my GMAT and application days.
First of all, I would start by checking out GMATclub. If I were to choose one website for GMAT preparation and help with the MBA application process, it would be this one. In addition to helpful study guides, it also has a forum where people share their GMAT and MBA application experiences.
After taking the GMAT, you need to begin to really focus on which school you want to attend. Besides reading a school's website and getting in touch with students and alumni, another way to research MBA programs is to read student blogs.
A list of student blogs
A list of applicant blogs
A list of alumni blogs
The Clear Admit blog
Admissions 411-Not really a blog, but a collection of MBA admissions stats
I would say that writing the application essays is the hardest part of the application process. Even if you have a 780 GMAT score, if your essays don't make you stand out you will probably be rejected. GMATclub is chock full of suggestions concerning application essays, but to get you started here is a free guide to writing application essays.
If you are lucky enough to be selected for an MBA interview, here are a few interview resources:
A list of common MBA interview questions
A collection of interview experiences for each MBA program
So, there you go. I hope you find these links as useful as I did. Good luck!