On the Microsoft websites you will find many opportunities to sign up for essential newsletters delivered directly to your e-mail inbox. There is one place you can go to subscribe and unsubscribe to all of these newsletters - the Microsoft Profile Center website.
There are many newsletters and the frequency of them will vary. These are the newsletters I would consider mandatory reading to keep up to date, in addition to the regular postings on this website BlogMS.
Click on the following link for further information about how to subscribe to Microsoft Newsletters on the Microsoft Profile Center.