Do some research. The Nikkor 80-200 or 70-300 VRG might meet your needs better. For most folks we need one or the other - for those that don't need either the 70-200 tamron is probably want they need. With the 80-200 or 70-300 VRG you are getting awesome lens on the cheap. If you've got camera buddies, then borrow lens from them to try them out. For actual fast action stuff, many (some of whom are rabid nikon fanboys) recommend the Tamron 70-200mm.
If you're really looking for value (performance vs. price) the Tamron 70-200 (fast action sports), nikkor 80-200mm (everything but fast action), or Nikkor 70-300 VRG (fast action good quality and cheap used) are alternatives. Don't think you have to buy an insanely expensive lens that might be something you don't need to fit in. There are very few people that need anything more than the Nikkor 70-300 VRG. I do ok in my job and buy a lot of stuff and the 70-300 VRG seems to be as good as I am and I spend my extra money for other lens (I haven't even considered buying the 70-200 from Nikon or Tamron). Nothing will break your heart more than dropping a fortune on one of the "trinity" and finding out for the price you paid you could have had an alternate to every member of the trinity (some of which are better than the trinity lens). This hobby isn't about who can spend the most money.
Research screw drive fast glass. Ebay is an awesome source for lens and I've never been screwed over. The camera you have purchased can use most of the famous lens that took the photos you ooo'd and awed over in Nat Geo in the days before photoshop. Enjoy your camera and remember the price of that 70-200 would be enough to get you everything you'll ever need if you do the research.