You can fill out the applications all at once or over a couple of days-your choice! Just as long as you send it in or drop it off well before the deadline, it's personal preference as to how you approach the applications.
When I applied, I started the West Point application in January and had it completed within the month. The second phase didn't open until the summer, and then the nomination applications became available from July - August depending on the nominating source. There's no official week by week checklist but dedicate time on the weekends to getting these things done because the faster you have everything submitted, the faster they can review it. When everything was said and done, I got my acceptance to West Point and the Naval Academy almost one year after starting the applications.
I would encourage you to take this time to make your own weekly/monthly schedule instead of relying on one that already exists. This is a skill that will help no matter what university you attend, but will certainly help you at any academy. Personal motivation and preparedness is the foundation of everything. Good luck!
