First the very basics: Goodin is 6'3" (or so) tall and weighs in right around 175 pounds or so. He is universally rated as a four-star player, in the top 100 overall in his class, and in the top 20 in his position. He was first-team all-state as a junior, averaging 21.3/6.2/3.8 on .509/.320/.745 shooting.
Goodin is a strong player who uses his body well both to protect the ball and get to the rim. He's a point guard by trade who can play off the ball as well, using his skills as a slasher as his primary weapon in either setting. I haven't read anyone who has watched Goodin play who loves his jump shot in general, but his does have the ability to knock open Js when in rhythm. His release is smooth and high when he shoots it well; consistency is largely his problem.
He is a right-handed player but can be effective moving to either hand, though he is a predominately right-handed finisher at the rim. He works well of a pick and roll, both using and turning down picks to unbalance defenders and get himself working downhill towards the basket.
He uses his body well on defense to harass opposing guards; he has the frame and abilities to become a force on that end of the floor as well. He's a willing rebounder who uses his size well on the glass. All in all, he's a solid pickup from day one with every chance to develop into a big-time player.