i have found the wedding channel message boards to be really helpful in my hunt for photos of various things. this is the direct link to the hair/makeup forum. you should be able to find threads for up-dos, half-ups, and buns/chignons within this forum - there will be plenty of pictures in each of the relevant threads.
"to be nobody but yourself in a world which is doing its night and day to make you everybody else, means to fight the hardest battle which any human being can fight, and never stop trying." - ee cummings