I have following tables

CustomerTable - customerId, Name, City, StatusId, TypeId

StatusTable - statusId, status

TypeTable - TypeId, Type

Now, how can i create Enum in CustomerBO to handle these 2 fields [StatusId,TypeId] and also bind the dropdowns in Customer webform with the complete list of Status & Types.

You cannot have a dynamic enum...enums are static.  So I assume you want to populate a combo from a business object and then bind to a foreign key.  First, you will want to populate the combo using a business object:  I am just going to point you to the help since it says a lot more than I can in this post: UI Layer -> Controls -> List Population

As for your parent-child relationships, look in the help under: Business Layer -> Common Business Object Tasks -> Defining a relationship between business objects

If this doesn't get you going let me know.