You see in the navigation bar, there's a tab labelled "search"? Click on it, and it'll display a box where you can add certain keywords to see if a particular thread has already been made -- results also display automatically when you enter the title of your own thread :3
Honestly, the search bar is kind of...well. There's always a lot of clutter to go through. =/ what I tend to do is go to google, put what I'd like to search between quote marks (if you search "does naruto eat ramen everyday" instead of does naruto eat ramen everyday, it will pick up your exact phrase and filter any unnecessary results), so your searches come up much cleaner xD
Edit - I meant to add, you should format your google search like this:
site:narutobase.net "does naruto eat ramen everyday"
^ doing that will search your exact phrase on narutobase only =]
