There was a thread on this last week and someone posted a good article on break-in. Some basic facts that most agree on are:
-The rings are broken-in in the first 30 to 50 miles.
-Rings need a fair amount of cylinder pressure to seat well.
-Make sure you warm up your engine to normal temp before you start your break in proceedure AND don't let the engine overheat. Stop and let it cool down.
-The rest of the engine break-in can take up to 3000 to 5000 miles.
-Vary your RPM until 500 miles, meaning don't cruise at one RPM more than a couple minutes.
-Don't lug the engine.
-Standard Oil (non synthetic) is better for break-ins.
Those are facts that most folks agree, give or take. Now how you break-in with in those facts is where folks disagree. Here is one break in that is more agressive than many here are comfortable with.