When you using worldguard select the area you wanna protect and type //expand up 300, then //expand down 300. Next type /region define (region name.) Then type /region addowner (region name) (your name). The next part is what you ARE NOT doing. you have to type /region f (region name) build deny. Then /region f (region name) construct deny. This makes it so only you can break and build on this area.
Hope this helps!
