For the Dutch TechNet magazine I wrote an article about the security within SharePoint. This is my first TechNet article and I think it has turned out great. The link to the article in included below.
Veiligheid in en om SharePoint – TechNet Magazine, juli 2010
Also read the article of a colleague of mine which wrote an article on SharePoint and Communities that was in the same magazine.
SharePoint, de virtuele koffiecorner – TechNet Magazine, juli 2010