I keep reading about this robot.txt file and as I understand it, it tells search engines which part your site not to crawl. Is that correct? Also, what is the exact code that needs to be copied into the website editor? I keep finding long-winded explainations that I don't completely understand, what I really need is code that I can copy and paste.

I keep reading about this robot.txt file and as I understand it, it tells search engines which part your site not to crawl. Is that correct?

Yes, essentially that is what it does. You should check out our search engine forums for more information.

You can also read more here: http://www.robotstxt.org/wc/robots.html