Custom List forms in SharePoint using Visual Studio

At times if you come across a requirement, where you need to use the default list form fields but in a different order, and maybe with some minimal business logic using server side code.  

Two very well documented articles mentioned below will guide you through the process :

http://blog.karstein-consulting.com/2010/12/29/walkthrough-create-custom-sharepoint-2010-list-form-for-deployment-in-a-visual-studio-2010-project/

http://blog.karstein-consulting.com/2011/01/24/walkthrough-create-custom-sharepoint-2010-list-form-for-deployment-in-a-visual-studio-2010-project-part-2/

Using before, after properties and properties.listItem in SharePoint event receivers

While handling business requirements in event receivers, we often need to handle common scenarios with before and after properties.

The behavior of these properties is different for a list and a library. Below is a summary of the behavior.

List:

List	BeforeProperties	AfterProperties	properties.ListItem
ItemAdding	No value	New value	Null
ItemAdded	No value	New value	New value
ItemUpdating	No value	Changed value	Original value
ItemUpdated	No value	Changed value	Changed value
ItemDeleting	No value	No value	Original value
ItemDeleted	No value	No value	Null

Library:

Library	BeforeProperties	AfterProperties	properties.ListItem
ItemAdding	No value	No value	Null
ItemAdded	No value	No value	New value
ItemUpdating	Original value	Changed value	Original value
ItemUpdated	Original value	Changed value	Changed value
ItemDeleting	No value	No value	Original value
ItemDeleted	No value	No value	Null