I get weird characters when I copy/paste from my pdf book

Everyone in my office has worked on a PDF book on their PCs. I got my hands on it and did an extensive overhaul on it, better details, graphics and whatnot.

I finally sent it out and they love the way it looks, but they cannot seem to copy correctly from it. It either gives weird off characters and numbers when one pastes or it gives off mis alinged parts of words.

I have tried taking all of the word documents and converting those on a PC and whatnot. I really dont know what to do anymore. I used preview on mac osx to build it with individual pages and it gave me the horrible paste characters. I put it together on windows, i have no idea what is wrong. I am thinking its my word 2008, but I exported a document with word 2000 (which the original books were made in) and its still doing it. I need some help please.