There are plenty of instructions like this around online, but they're all unnecessarily complicated and many use difficult or imperfect methods to cut the bottle. These steps are the simplest and most effective way I've found. I can cut a wine bottle in 2 minutes tops.
Step 1: Select Bottle/Remove Label
Start out with a wine bottle. They seem to be the easiest. Beer bottles are thinner, and crack more easily.
To remove the label just run under or soak in hot water. I used a metal spatula to scrape it off and a scrub brush to remove to glue.