You can also just trace the shapes as you would when working on a vector graphics software. It would depended on what you’re trying to achieve, if you want the logo to actually flow in all three axis, but as it’s a logo, all the pieces can be flat in the Y axis and extrude them in Y to have some solidification. JL went through that workflow in this lessons:
https://cgcookie.com/lessons/modeling-a-logo-pt-1
