Forms Based Authentication in Sharepoint

How to configure FBA in MOSS 2007

To configure FBA in MOSS 2007, you basically need to extend your webapplication and add your membership & role provider.

Here you go  http://msdn.microsoft.com/en-us/library/bb975136.aspx

How to configure FBA in Sharepoint 2010

To configure FBA in SP 2010, you need not extend the current webapplication. You can create a brand new webapplication with claims enabled and can have FBA. Additionally you can have Windows Authentication too under claims.

Here you go http://technet.microsoft.com/en-us/library/ee806890.aspx