Regarding legacies:

If your mom was initiated into an NPC sorority, then yes, you are a legacy. She can check on her status by contacting her HQ or logging on to their website. Sororities often have a "Legacy Introduction Form" (or something to that equivalent) that they ask their members to fill out when their legacies go through rush.

And as far as listing it on your recruitment application, check out this thread:
http://greekchat.com/gcforums/showthread.php?t=70089 and hopefully you can decide for yourself which is the best way to go. I definitely don't blame you for being on the fence on this.

Regarding recs:

Ask your teachers, family friends, people you know in your community/church if they were Greek in college. Another route would be to visit www.npcwomen.org and get contact information for your nearest Alumnae Panhellenic Association. You'll want to start putting together a resume for these women.

Regarding the new colony:

Based on what I've read here, new colonies conduct recruitment after the existing sororities are done with theirs. Don't quote me on that because that's just what I've read here. I'm sure their recruitment dates will be posted once it becomes available. Don't hesitate to contact the Greek Life office.

Don't stress out on this too much. Just because there are more unsuccessful rush stories here doesn't mean that you'll go the same route. There are tons of girls who get bids each year that we don't get to hear about.