I have a MacBook Pro early 2011 and my hard drive is failing, I was wondering once I replace the hard drive, is reinstalling the OS X as easy as turning it on and booting into Internet Recovery, formatting the drive, and just reinstalling OS X?
I just did this yesterday (I have a slightly older MBP) and wasn't able to boot into Internet Recovery mode without mounting the old drive using a USB sled.
According to Apple your Mac should support Internet Recovery with a firmware update:
If for some reason you can't access Internet Recovery the alternative is you can mount the new drive externally and use Internet Recovery to install OSX on the new drive before swapping them but the install process will be a bit slower since the drive is external.
Hopefully you're planning on installing an SSD, I installed one and it made a huge improvement on the speed of my Late 2009 MBP.