I would recommend changing the word "mock" test for "practice" test. Also, it might be good to take the GRE at the end of September or by mid October in case someone decides they want/need to retake it.
Also, around August you should start contacting the professors, before the application process begins, not after! It's good to have them on your side when the application comes around, plus, some universities require faculty sponsorship. It's also good to contact possible advisors in advance in order to know if they'll be taking students.
Contacting other grad students in advance is also helpful since they can give you inside information about the school, the environment, the professors, and might even give you application tips.