This is very simple once you know how...

First, get yourself a PDF Creation software. If you want a really good one, just go to http://www.pdf995.com/, and it's 100% free.

1. Install your PDF software
2. If you are using MS Word, then open the document in Word (this can be .rtf documents as well).
3. Edit the document howeever you plan too.
4. Click on (top left of MS Word) File>>Print
5. Select "PDF SOFTWARE" as your printer. If using above software it will be "PDF995"
6. This will print the document as a PDF only (No paper), and you have your new eBook.
   

Note: There is a free PDF creation software at www.pdf995.com that you can also download for securing your document and other things..