Adding more documentation

docs/Define-Maps.rst

@@ -7,7 +7,10 @@ There are three interfaces that enable the definition of mappings making;
 2. IMapFrom
 3. ICustomMap
 
-The first two enable the definition of simple mappings i.e.  If you have a database entity and domain entity 
+IMapTo & IMapFrom
+------------------
+
+The IMapTo and IMapFrom interfaces enable the definition of simple mappings i.e.  If you have a database entity and domain entity 
 that may have the same properies  eg.
 
 A database entity that has two properties
@@ -43,4 +46,39 @@ interfaces to define the mappings
         public string Description {get;set;}
     }
 
+Once the interface has been implemented and the designated class name supplied there is nothing else you need to do to implement the mapping.
+The automapper libraries take care of all the mapping for you.
+
+ICustomMap
+----------
+
+The ICustomMap interface is required if your objects require more complex mapping logic.  The interface requires
+the implementation of a mapping method
 
+::
+
+     public interface ICustomMap
+    {
+        void CustomMap(IMapperConfigurationExpression configuration);
+    }
+
+It is in the CustomMap method that you can use all the power and functionality of Automapper to implement your required mapping logic
+
+::
+    
+     public class ComplexDomainObject  :ICustomMap
+    {
+        public string Firstname { get; set; }
+        public string LastName { get; set; }
+        public string Summary { get; set; }
+        public string Title { get; set; }
+        public int Age { get; set; }
+        public void CustomMap(IMapperConfigurationExpression configuration)
+        {
+            configuration.CreateMap<ComplexDomainObject, SimpleEntity>()
+                .ForMember(dest => dest.Name, opt => opt.MapFrom(src => string.Concat( src.Firstname, " ", src.LastName )))
+                .ForMember(dest => dest.Description, opt => opt.MapFrom(src => string.Concat( src.Title , " ", src.Summary)))
+                .ForMember(dest => dest.Age, opt => opt.MapFrom(src => src.Age));
+               
+        }
+    }