Hi Marilyn,
I had a scrupulous scout in Nashira, and I
loved playing her. You are completely right: good alignment shouldn't and doesn't stop you from worshipping Nashira in any way, shape or form. Mind you, you might run into several dilemmas where enmity and alignment will clash with your character's devotion to her goddess, but that sort is in my opinion the *good* sort of controversy - ie. the roleplay kind.
You should always give careful thought to how your girl would react. I belong to the group of players that don't think lighties would necessarily turn their backs to darkies, until they have proof of their evil-ness (this is different from enmity though, which is inherent and should never be ignored). Especially a young lightie might be naive enough to think that evil can be "cured", that kindness can cure blabla. All depends on your character concept.
As for the astral boards, seek out an experienced bard or perhaps one of the more known mages - they can explain the IC contexts to you. OOCly, they are simply (as drewbag said) global noteboards.
Welcome to SK!