Hokkaido Rail Pass

I would like to buy the Hokkaido Rail pass and there is some question for me?
1) Can i buy the Hokkaido Rail pass in New Chitose Airport?

2) How many days in advance can i make the reservation seat for Hokkaido rail pass? For example:- i using the Hokkaido rail pass from 10/7/14 to 14/7/14. Can i make all my reservation seat for my 5 days trip (10/4-14/7) on 10/7?

3) Where can i make the Hokkaido Rail pass reservation seat? What is the reservation seat counter business hour?

4) How can i know which is reservation seat when i prepare getting in the train?

Thanks

Regards,
CC

1) Can i buy the Hokkaido Rail pass in New Chitose Airport?

Yes, at New Chitose Airport Station JR Information Desk (open 8:30 - 19:00)
http://www2.jrhokkaido.co.jp/global/english/railpass/rail02.html

How many days in advance can i make the reservation seat for Hokkaido rail pass?

From one month in advance, but only after you have your actual pass purchased/exchanged.

For example:- i using the Hokkaido rail pass from 10/7/14 to 14/7/14. Can i make all my reservation seat for my 5 days trip (10/4-14/7) on 10/7?

Yes.

3) Where can i make the Hokkaido Rail pass reservation seat? What is the reservation seat counter business hour?

At JR ticket counters across Japan. They are usually open from the first train of the day (typically around 5am) to the last train of the day (typically around 1am), although it depends on the station.

How can i know which is reservation seat when i prepare getting in the train?

There are signs just like in an airplane. The cars are also numbered.

Basics on using trains:
http://www.japan-guide.com/e/e2016.html