SQL security

What is a SQL Injection Attack?
This article describes what a SQL injection attack is and what it does. If also gives a simple example of how the attack works.

SQL Server nested securable permissions
I know that in SQL Server 2000 and below, you could assign permissions against objects like tables, views, and stored procedures. I'm hearing in SQL Server 2005 and 2008 there's a new security model called securables which allow for nestable permissions. How does this work?

SQL Server Security
There are several levels of security to SQL Server. At the base level, in order to be granted get access to a SQL Server, a user is required to have a login account. There are two modes of security to SQL Server, distinguished by which program provides the authentication.