I have a D3100 and consider myself a novice at shooting with my DSLR. I currently have the lens that came with my camera, and I also have a AF-S 50mm f/1.8G. I am looking to get a lens that's going to give me the reach I'm looking for. Mainly going to be shooting my son, landscape (Vacation), and Sports Events. The Lens I looking at is the 18-200mm, 55-200mm, or the 70-300mm. Which one would be best?