Here are some things to start working on given the amount of time you have:
Improve Your Resume
Take advantage of the additional time by really focusing at work. Improving your performance and taking on additional leadership opportunities affects so many different application pieces. From your resume to the recommendations to even your essays, being a rockstar in the office is one of the best things you can do with the additional time.
Identify Recommenders
This is usually one of the last decisions candidates make when it comes to the application and it really should be one of the first. Picking a recommender is not just about having someone fill out the form. In the best situations it is someone you trust and have built a close professional and sometimes personal relationship with. If that person does not exist, then its time to start identifying and preparing someone for the upcoming application season. Recommendations are very time consuming so make sure you are identifying someone who is not only willing to dedicate a good amount of time to these but also who puts a strong representation of you forward.
Take the GMAT
Get the GMAT out of the way as soon as possible. Nothing distracts qualified applicants more often than trying to prep for the GMAT while working on essays and other application components as an application deadline approaches.
School Selection
One of the easiest things you can do with the additional time is finalize your school list. Start broad and narrow down using a filter of what you are looking for in a school like location, academic programs, reputation, etc. Once you secure your GMAT score you can kick the school selection process into high gear. Engage in some primary research by visiting schools and getting a more in-depth understanding of your target programs. This will also help you develop some real essay and interview fodder when discussing “fit.”
Essay Prep
A lot of schools change their essays every year. Others keep them pretty consistent with slight tweaks. Either way it won’t hurt to get a head start on looking at the type of questions your target schools have historically asked. This will help you as you start sorting out potential approaches to the essay portion of the application. Also, there are traditional essay questions that will be asked in one form or another in almost every application like “Why MBA”. “Why School X”, and “What Are Your Short Term and Long Term Career Goals?” You know these questions are coming so get a head start on answering them.