Yes, most phones have internet access, but I strongly doubt most people have that included in their monthly plan - I know I don't. So do I have to pay extra ch

Yes, most phones have internet access, but I strongly doubt most people have that included in their monthly plan - I know I don't. So do I have to pay extra charges for that? How much data is being sent? Can I view stats on my phone? Can I tether my phone to my computer to look at stats? I can't find any of these answers on their site. Which is frustrating, because this almost sounds like something that would interest me.