[Zope] upload into a ZObject

Does anyone know how to upload a file or an image into a ZObject? I have created a simple ZClass that makes ZObjects to simulate book information like title, author, etc. I have selected to upload images and files into the ZObject, but I don't have a clue what dtml codes I should use to do that. Can anyone give me some pointers?? Also, if I have a book object that was stored in either one of two folders a and b (assuming don't know where) and I need to get its internal information like the book title and author, how do I look for it using dtml??