To root your Nexus phone, you should start with learning how to install and configure the Android SDK. There are plenty of one-click scripts or toolboxes that will unlock your bootloader and get you ready to flash (or even flash it for you) a custom recovery, but there’s a great reason to learn how to do it yourself — you are able to fix most anything if it goes wrong by using the Nexus Factory Images.
Google not only supports unlocking your bootloader, they also give you full and complete instructions on how to do it, how to flash third-party images and how to go back. Unlocking the bootloader doesn’t break any warranties as Google realizes that there are many valid reasons to flash experimental on the developer/reference device for Android. Take advantage of this, and use the tools Google provides!
Once a third-party recovery image is flashed, you’re easily able to push anything you need for root or any other image to your Nexus. Because it’s the reference phone and easy to alter, you’ll find plenty of tools and resources for things you can do after you’ve rooted. We highly recommend a Nexus phone to anyone who wants to tinker with the Android software platform.