[NaS]

There are other applications that use PAWN as scripting language and many of them also have a forum or wiki.
You must be careful with application-specific information but if it's about the language itself any tutorials from there will be as useful as the ones here on the SAMP forum.

For example https://wiki.alliedmods.net/Pawn_Tutorial is much better than the one on the SAMP Forum imo (it's also linked there)