I can't especially think of anything that you would break even during a first time build. Everything is designed to prevent insertion if it's aligned wrong. Just remember to plug in your CPU fan in the right place and add your thermal paste properly to the CPU before you place your heatsink (and remove the stock paste from the bottom of the heatsink). Even if you forget to the system will just shut off though. It won't damage anything. You'd have to be the hulk to crack your motherboard during a video card installation.
You'll be really pleased with the end result and get much more bang for your buck if you build. Plus, if something does go wrong in the future, you'll be much more familiar and able to diagnose and replace your own components.
You'll be really pleased with the end result and get much more bang for your buck if you build. Plus, if something does go wrong in the future, you'll be much more familiar and able to diagnose and replace your own components.