Look to keep all items small and multi-purpose if possible.  I have a girl friend who drives me crazy by bringing the full, maximum size, shampoo bottle from her bathroom...you only need one or two dollops of shampoo for the whole trip!  Another fellow on his first trip brought a big hardcover computer book, several magazines, a radio and his rechargeable shaver.  He used the radio, but the rest never got used, had to be dried out once when he turned over the canoe, and he never found the time to read a page, much less a book.
I usually bring a small book, like a paper back, but still hardly ever get a chance to read.  One camper girl friend of mine brings a paperback she doesn't care if she brings home, she rips the pages out as they are read and always has a little paper to start a fire.
I would bring your own pack as opposed to sharing a pack with someone else.  This avoids packing hassles and bad feelings if your stuff gets wet and you think it's the other person's fault.  
It is absolutely imperative that you have a dry set of clothes in reserve for emergencies; and as said previously just knowing you have them as a back up allows you to spend all day in cold wet clothes if necessary and you can save yourself once at camp for the evening.  ;)