I am new to the dslr world. I have the sony a200. I am a very novice photog mainly just close shots of the 1 year old. I also play competitive softball and I would like to get some action shots out at the field.

I am looking to get a telephoto lens. I have the sony 70mm that came with the camera. I also have an older tamron 70-210mm telephoto from my old Minolta camera. Will this lens do? If not what should I look at?

Also what are the thoughts on getting a 28-300mm lens. Since I am just novice is it a bad idea to just have one lens to capture all the shots I would need?