Thinkin' 'Bout Betas

Today, when my beta saved my ass, suggesting that I toss the last 2,000 words of my latest chapter and go another way, I got to thinking about the importance of betas.

What makes a good beta?  What are the rules for betas?  I’ve been writing for such a short time that I’m just learning my way around it – to be honest.  But I have some thoughts about how critical betas are and what makes a good one – and I’d love to hear anyone else’s thoughts on this.

( So what makes the beta-author thing work, ya newbie? )