How to efficiently "search" within forums??

[TROXZILLA]

I am relatively new to this site but how in the heck do you search for certain key words within threads? For example if I wanted to search for all threads that contain the word "berks" is there some specific way to do this? Every time I use the search function it never pulls anything up. Even if I use an advanced search. I just get this message saying "nothing found". Even though I know there are probably a hundred threads out there that contain info on berks products. It's driving me crazy. And I couldn't find and threads or forums on "how to use the search function". Help!!!