Unlocked HTC One question

I'm thinking about buying an unlocked HTC One and putting it on Straight Talk. I know nothing about smartphones (Only had the 1 I currently use), and I've always been with Verizon. That plus I'm very un-tech savvy, means I know basically nothing about all this unlocked, AT&T/T-Mobile sim, etc. stuff that I've read when I searched online about getting the HTC One on Straight Talk.


Now that you know I have no knowledge whatsoever, I'd like to know what is the process, and what do I need to do to get the HTC One on Straight Talk? What is the difference between the ATT&T and T-Mobile sim? Which is better and which should I go with. I know these may seem like dumb questions, but as I stated I have no knowledge (We all have to start from somewhere), and as this will be a pretty big purchase to buy the phone outright, I don't want to have any mess ups. Also, I live in the Eastern United States (Maryland). Does anyone know if I will get decent coverage in this area? The main reason I want to get Straight Talk is so I can get data cheaper and stream music more often from Pandora, so if you know that I can't get good signal I won't even bother.

I look forward to reading your responses and chatting to learn more about this topic. Thank you in advanced for your patience in helping me with this.