What carrier plan should I use for my iPhone?

I'm going to get a 32 GB iPhone 5C (green, so excited!), but I have no idea what plan to get. I have one modern, intelligent family member to do a family plan with, a sister who is getting the same thing. I heard from a friend that Verizon is doing a family plan for her to where she has to pay $45 for unlimited data. I would need a plan with 4G unlimited data and only about 600 minutes per month. By 4G, I hope that I'm talking about super fast internet. I honestly am one of the dumbest people in the world when it comes to technical stuff, so you simple terms please. I don't' necessarily need Verizon, but I need a carrier that has good service, fast internet, employees that I can understand over the phone, and a plan with UNLIMITED DATA at a little less than $50 a month! I heard Virgin Mobile and AT&T are doing plans like that. Also, what warranties should I get? I'm not concerned with loosing it or having it stolen or chipped. I only want to replace it if I dropped and shattered the screen or cracked it to much. I also am considering getting it at Best Buy.

Hard to go wrong with verizon or at&t or sprint, but other carriers that aren't as big are cheaper like striaght talk

Neither Verizon nor AT&T offer unlimited smart phone data plans and haven't for years. If you can only afford $50/month, you're not going to have a choice, Virgin is the only carrier that's that cheap.

As for warranties, warranties only cover manufacturer's defects and software issues. For physical damage, you need insurance and you need to make sure you know exactly what each policy does and does not cover and what your deductible is. Square Trade and Worth Avenue are two of the more popular insurance companies.