So I have seen cellular modules on the market I've never had one or really understood them so I have a few questions. I dont know much about wireless interfacing so i may sound like a newbie.
If you could answer as many as you can please.
what should I be looking for if I just want to relay a bit of info over long distances every so often?
do you need a "network" like verizon or something to use them? (I'm gonna guess no)
how would an arduino communicate with one? Through spi, i2c, or what?
So the payment would just be the sim card, I wouldn't need a plan or something, right?
Typically, the price per minute depends on just how committed you are as a customer. Very committed (got a plan) == low price. Uncommitted == high price.