Another free book from our Patterns&Practices team about something that you know you ought to know a little about :-) - Claims Based Identity and Access Control.

Get the Book here - http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=4c09ffe4-43dd-4fcc-be35-c897c9bc4386
Code samples here - http://www.microsoft.com/downloads/details.aspx?familyid=33829BCF-F5EA-4650-B807-57C63A753753&displaylang=en