There is a living document available online that will be managed by the CRM Product Team that will give you guidance on the Microsoft Dynamics CRM Stack Technology Compatibility.
Do you want to know if certain Service Packs or versions of a Microsoft product are supported with Dynamics CRM? Now we have all of this in one “living” Knowledge Base article: the Microsoft Dynamics CRM Compatibility List. For example, you can use this KB article to determine the latest Microsoft SQL Server major version and Service Pack that is supported. Microsoft lists new products like Internet Explorer 11 and Microsoft Windows 8.1 as TBD until testing is complete; generally near General Availability (GA) of that product.
A snippit of the page for CRM 2013. This is definitely a page you will want to bookmark.