Investigate Buying Options
You'll also want to investigate data plans and how carriers sell their smartphones. Each has its own branding and its own way of doing things and you'll want to look into all of this now so you aren't confused when release day arrives.
You'll want to compare the two-year contract, if the carrier even offers it, to plans like AT&T Next and Verizon Edge. Carriers are going to try and push you to these new plans and you'll want to be ready for that once the Galaxy Note 5 arrives.
More importantly, these plans have changed since they were first introduced. So if you haven't been paying close attention in 2015, you'll want to dig in and figure out which one is going to be best for you. You won't be able to do this in a day so you'll want to start wading into the red tape right now.