I bought this book a few months ago and it's improved my desing ability 10x. Then I started reading up on unit testing. I decided I would look at unit testing as I coded a website. How can you go about unit testing business objects methods when all the business layer objects create a new data layer object within most methods. I've been racking my brains on how to change this around but then I thought does a solution like this warrent unit testing? Any commnets on this would be very very appreciated!
I'm using NUnit if that helps. I've read a little about Mock objects which seem to be close to what I require...but because the data objects are created within the methods and not passed in this seems like its not the correct solutuion.
Cheers for any help!

You should first write unit tests for your DAL objects. Once done, you write unit tests for your business objects. Yes, the business objects will call DAL functions, but so what? You need to test the business objects as black boxes. You give it a known set of inputs and you expect a certain set of outputs.

If a business object fails a test, the actual problem might be in the DAL or DB, but the fact remains that the business object gave you a red light. Hopefully your DAL tests will tell you if the problem is at that layer. But regardless of where the bug is located, the user of the business object sees that he's not getting the expected result, so the unit test still has validity.

Unit tests can help you find bugs, but they don't take the place of traditional debugging techniques. If they did, many of us would be out of a job!

cheers englere. thanks for the advice.