CIB can mean two things depending on who you ask. It technically mean Cart Instructions Box, but others refer to it as Complete In Box, usually meaning cart, instructions, box, maps/posters, etc. Most CIB ames are just Cart, Instructions, Box, but others like a lot of RPGs came with a map or an item sheet of some sort, and some games came with a poster. Some posters were found in multiple games, others are specific to that one game.
I'm not sure if there's a way to tell if it is all originally together or pieced. Most I guarantee you are pieced together seeing as lots of boxes were chucked, same with manuals, but more so the boxes. You can always look up certain things on the net and find out if there's differences between 1st print runs of CIB games and later print runs. Some have corrections to words like Final Fantasy 7, so have a slightly different color or word font, all depends really. Most remain the same throughout their print run with obvious exceptions like Player's Choice games which are distinctly different than their earlier releases. Manuals would be the hardest since they usually never change.
Books/Boxes/Maps/Posters, etc all have an impact on the value of your item(s). Some more so than others, like a sports box/manuals usually never fetches you more than a few bucks to the game. But a box for a game like EVO, Super Mario World, Stadium Events, etc. Ups the value immensely. Some instruction manuals are worth more than boxes. Usually not the case since the box is more desired, but for certain games (can't think of any right now) their manuals are the difference between a $40 game and a $200 game and manual. The pamphlets aren't really valuable at all since there's plenty out there and lets face it, how many collector's care about them compared to manuals and boxes? Foam blocks for NES games are preferred since it makes everything fit and the cart doesn't wobble around in the box, creating more wear, same with trays for N64/SNES games.
Good luck and hope this give a bit of insight on collecting and such.