LinqToSql and DataContext 101

I'm looking for a good article or two, or just an explanation of how the DataContext, or the dbml file for LinqToSql, exactly works in LinqToSql.

• Is this a disconnected environment?
• Are the database connections bound to the Sql server?
• If I create an instance of my DataContext, am I responsible for deleting it?
• How does it handle multi-user environment, when my application creates a new DataContext object, each thread gets its own DataContext?

And a bunch of other questions, as well as some best practices!

Any help would be greatly appreciated!