Are LDS church manuals considered to be the words of God?

In some manuals I've read in the intro that it is official church doctrine, and in some books written by apostles (like Miracle of Forgiveness) it says it's not official church doctrine. Anyway, if a manual (not just any lds book) doesn't specifically say that, are all manuals considered 100% official church doctrine anyway? Seminary? Institute? Everything? And does that mean they're considered to be the words of the apostles, which would mean they are the words of Christ? E.g. I have heard some (Beginning Phase, Conclusion) of the history of making Preach My Gospel, the manual for missionary work. >President Boyd K. Packer said Preach My Gospel was “designed beyond the veil and put together here.” From that (along with other spiritual experiences) I can tell it's the word of God, but in the First Presidency Message it doesn't specifically say that. I'm a little lazy to be researching the making of every manual. Sorry, this is probably a dumb question that I could figure out by common sense, but it would be nice to have references to back it up. Aside, Maybe I have this question because I don't fully understand the difference between canonized scripture and the word of God in general (I haven't looked into that very deeply)?