Travel to Sapporo from Tokyo

I am planning on going to Sapporo on Sunday in November. I would like to know:

1. How many days in advance do I need to book my tickets for November?

2.I am looking at Skymark Airline at 11am or Vanilla Air at 11:45am, which one is better?

3. If I am taking the Skymark airline, When do I have to be at the Haneda Airport by? Will 10am be good enough?

3. What is the best way to get to Haneda Airport from Hanzomon Station?

How many days in advance do I need to book my tickets for November?

None. If there are vacancies, you can buy them just before departure at the airport. Generally speaking, however, the earlier you purchase, the cheaper the ticket.

2.I am looking at Skymark Airline at 11am or Vanilla Air at 11:45am, which one is better?

It depends on where you want to fly (Skymark flies to Haneda ad Narita, I believe; Vanilla to Narita only) and the price offered.

If I am taking the Skymark airline, When do I have to be at the Haneda Airport by? Will 10am be good enough?

I recommend 45 to 75 minutes before departure.

3. What is the best way to get to Haneda Airport from Hanzomon Station?

There is no easy way:
http://www.hyperdia.com/

Thanks UJI,

1. Do you know when will they start selling tickets for November??

2. I just want to know is there a lot of difference between Skymark flights and Vanilla Do flights?

Do you know when will they start selling tickets for November??

It depends on the airline. Skymark starts 2 month in advance. Not sure about Vanilla.

2. I just want to know is there a lot of difference between Skymark flights and Vanilla Do flights?

No. Both have relatively liberal luggage policies for low-cost airlines. The main difference is that Skymark flies into Haneda, while Vanilla does not.