Ask HN: Good blogs or books about growth hacking with Twitter?

For the next few months I need to focus on product development & fundraising. Twitter is the only social channel we rely on for growth, and I’m thinking about outsourcing it to a summer intern who spontaneously landed in our path. He has zero experience with Twitter, so I’d love some good reading materials to get him started thinking about growth & metrics focused social media marketing. Not my specialty at all, so would appreciate any general feedback on this plan.