JR pass, tokyo to sapporo

i would like to travel from tokyo to sapporo, through the seikan tunnel on my JR pass. When i get to tokyo:
1: how can i tell which trains i can use on the JR pass,
2: do i have to book in advance
3: i believe i will need to catch connecting trains, is that hard to organize?

-Quote-
i would like to travel from tokyo to sapporo, through the seikan tunnel on my JR pass. When i get to tokyo:
1: how can i tell which trains i can use on the JR pass,
2: do i have to book in advance
3: i believe i will need to catch connecting trains, is that hard to organize?
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#1: You can use the pass on all the trains below.

2: A reservation on the Shinkansen Hayate is mandatory. When all the seats are booked up, standing tickets start to sell. As for the other trains, they have the free-seating section.

#3: Refer to the connections below.

Tokyo--(Shinkansen Hayate)--Hachinohe--(limited express Hakucho)--Hakodate--(limited express Hokuto)--Sapporo

6:56hrs - 10:03/10:15 - 13:14/13:29 - 16:58

7:36 - 10:39/10:50 - 13:58/14:13 - 17:29

8:56 - 12:03/12:16 - 15:12/15:23 - 18:59

10:56 - 14:03/14:15 - 17:33/17:55 - 21:31

12:56 - 16:03/16:14 - 19:20/19:42 - 22:56

There is one more connection which involves an overnight train ride (seats available on top of berths).

Tokyo 17:56--Hayate--20:59 Hachinohe 21:18--limited express Tsugaru--22:18 Aomori 22:42--express Hamanasu--6:07(+1) Sapporo