Nitrogen as acceptor of hydrogen bond

Hi all,

I am wondering which nitrogen could be an acceptor of hydrogen
bond(sp1, sp2, sp3, with formal charge "+", from amides or any
other...), and why?
This is probably the case of lone pair, am I right?
And which nitrogen can not be an acceptor of hydrogen bond, and also
why(If it is possible) ?
I would be very grateful for any informations and help.
Best

Tomek Wlodarski
.