If it's just a "planning my first startup" stage and not an existing enterprise of some non-zero size, I'd suggest starting from the book "The Lean Startup" by

If it's just a "planning my first startup" stage and not an existing enterprise of some non-zero size, I'd suggest starting from the book "The Lean Startup" by Eric Ries and other general "startup mentality" information sources. For a tech-minded CTO, it's especially important to have that correct "startup mentality" to avoid big mistakes from the start.