that's something I fear as well! I sent her my goodreads link though so she could see which books I have in my "read" so I think some people look at that and make sure you don't get a repeat :)
The machine sent me here. If your friend recommended brandon, she probably knows where to send you next - the simplest way is to just go by publishing order. If you want another very easy individual book that you'll enjoy at least as much as Warbreaker, 'Tress of the Emerald Sea' is the next go-to option though.