Maybe I am not understanding the question properly, but wouldnt you use the App.Config file?
To answer the second part of your question. When our program is compiled, a DLL of the class library will be created, you will have to move that DLL with your program!
EDIT:
http://msdn.microsoft.com/en-us/library/ms184658%28v=vs.80%29.aspx[
^] -- Just a little bit of info on the App.Config file! Have a click around to find out stuff you need to know.