Droid Razr Maxx HD Verizon activation question

[acarpediem]

So I have had an HTC Incredible for several years and I am ready to take the plunge for a new phone. The battery life was always pretty bad on my incredible and now I can not even make a half a day at work without charging (battery shot). So I did my homework and I really like the Motorola Razr maxx HD because of it's battery life. I looked at the Galaxy 3 and a few others but did not feel the differences outweigh getting the better battery life. So I found Amazon wireless has an incredible deal of $99 (compared to $259 at verizon). I am not a particularly techie person so before I pull the trigger I want to a make sure of a couple things.
I am the account holder and have 4 lines. We have two lines that are eligible for upgrades (not mine because I used it to get my son his iphone a year ago). With Verizon, this is not a problem. I am just a little nervous how this works when buying the phone through another vendor as I have never done that before. I will have to buy it under my son's number, so I will have to activate it as his to get the discount. So can I do this myself online? Do I need to go into verizon to switch it all back how I really want it or can I do that myself (I think I can online)? Is there any charges if i do it? I hate to sound like such a Noob, but I guess I really am!