It's sort of pointless to message the channel to search for a book, along with a timer. What you really need is a trigger flood, and that's what matters the most though, as you don't want to get flooded off or banned when someone send you multiple triggers at a time:

on *:TEXT:!googlebooks*:#:{
   if (!%goo) {
   inc -u4 %goo
  .msg $chan [GoogleBook] -> $+(http://www.books.google.com/search?q=,$replace($$2-,$chr(32),+))
   }
}