Read some of the other threads, and post or make viewable your stats if you want specific comments and advice. But in general, around 17:
-You should already have speed up to the 48 point soft-cap
-you should have agility and vision in the 30s at least
-tackling, catching and jumping should all be at least in the mid 20s, if not give them some daily training love. You DON'T need really high catching to make deflections or catches; raising it up high is mainly for WRs who want to avoid drops
-Super Vision, Shutdown Coverage (if your team plays man-to-man coverage) and Sticky Hands are all very good SAs to take.
-Confidence doesn't seem to be very important. Though if you find yourself getting burnt early in the game a lot it might be worth training a bit (not spending skill points on though)
GL, and hope you get a lot of Picks!