IS there code I can put into a page .. or a file that I could put into a directory which doesn't allow search engines to pick that page up. I have a certain directory on my homepage which would preferably be left alone by search engines and not be able to be searched...
yes it is... do a google search for "robots.txt" this is the file you will need to create in order to stop search engines from looking at certain directories and files. It's pretty simple to create and there is a ton of information about it.
Remember that some rogue search engines (and other types of bots, ie spam bots) completely ignore the robots.txt file. The major ones (Google, Yahoo, MSN) obey it (I'm pretty sure they would anyway).
If you want to completely protect it, you'd need to either password protect it, or use one of those images that has obscured letters/numbers on it that the user has to type in.