The 17th card is placed separately as the "starter."
Your total score is the sum of all 8 columns and rows, using the starter card as the fifth card for each.
You get 2 points for each 15, 2 for each pair, 6 for a Prial, 12 for a Double Royal Pair, 1 point per card for a run, 4 points for a flush not including the starter and 5 points for a flush that includes the starter, 1 point for a Jack that is the same suit as the starter, and 2 points if the starter is a jack.
Keep in mind that scoring in cribbage is done for every unique combination. So 3C-3H-3D-4S-5H scores 2 for each pair: 3C+3H, 3C+3D, 3H+3D, 6 for the Prial os 3C+3H+3D, 3 for each of the runs: 3C+4S+5H, 3H+4S+5H, 3D+4S+5H. So a total of 21 points.