Mentorship is one of the most effective business tools out there. Right now, in Miami, a program called Girls Make Beats is partnering professional DJs with more than 80 girls to help them refine their musical skills and potentially jump-start music-industry careers. Even Marc Benioff of Salesforce.com has lauded the value of mentorship. Today, Benioff is worth more than $4 billion, thanks in part to his having been mentored by Steve Jobs -- without whom, Benioff has noted, Salesforce.com wouldn't exist.