hiya..welcome to the cel collecting boat.

 If you put the cel in a cel bag, and then put 
the bag in the book. Your all set. Some people 
like to cut a corner off the cel bag(not while 
the cel is in it of course) so that the cel won't 
get condensation or other stuff, and the cel 
will "breathe"
Cel paint is going to stick to everything(it was 
made to), but it is much easier to pull a cel up 
from the plastic of the cel bag, than from the 
lovely line work of its douga. Cel paint WILL 
adhere to paper, usually in a way that will make 
you frown.
  So try not to put naked cels (without bags)in 
your cel book on the black paper directly.I dont 
trust the black dye they use in the paper for one 
thing,and for another thing if your cel chooses 
to stick to it you'll have a rough time 
separating it again.
  As for tissue. It gets stuck just as easily as 
anything else,easier it seems because its so 
frickin thin, so personally I HATE tissue and I 
will cut a cel bag to put between the cel layers 
instead.
I hope this was helpful.

Pale