config clarification e news letter

Well... woaw !!!!

This is gooooood !

Just to be clear what is the meaning of that :

Limit send: (CRON) (0 or blank for unlimited)
Emails per (CRON) ('Never' - not use CRON for send emails)

is it the number of mails sent and pause bentween 2 sents ?

And

There is some kind of tutorial in order to create templates ?

And....

Is there a way to make templates availabe ONLY for a specific site ?