Factory Pattern (How to use correctly)

Hi all,

I am looking at Factory Pattern and I'm having a little difficulty working it out.

My basic problem is that all of the examples I have looked at only contain classes with one method and no properties in any of the classes.
Is this a requirement of the Factory Pattern that all classes must implement the exact same interface with no properties?

For example:

interface IDog {
 String Bark()
}

class Bulldog : IDog {
 String Bark()
 {
  return "WoooF";
 }
}

class KingCharles : IDog {
 String Bark()
 {
  return "squeeky woof";
 }
}


Then I use the Factory to create the dog I want based on a parameter passed to a createinstance method and return the newly created type of dog. Then I can call the Bark method through the interface. Perfect...

So what is my problem....
I think the real problem is that I cannot see when or how to use this in a real world situtation. Now I don't know if the next bit is way off the mark but this is what I am trying to do...

I have an interface called ICompany. This has properties like Id , Name Address1, Address2 and Methods Retrieve, Create, Update, Delete.

I have a second interface called ILeader. This has properties like Id , Title, FirstName, LastName and Methods Retrieve, Create, Update, Delete.

I have created the implementation of these interfaces which connects to the database and all works as it should.

What I was looking at doing was creating a class factory for these two interfaces.

So my questions are:
1: Is this a viable / possible solution?
2: How would I go about this?
3: If what I am asking s not doable what would you do to hide the creation of these objects from the business or client code?

Hope this makes a little sense.

Darren