Dummies guide to updating graphics drivers?

 Hi there

 My machine is new and so needs some drivers updating to get it up to date. I'm new to switchable graphics though and wanted to know the correct way to upgrade both graphics drivers? I have been updating Windows 7 itself and one of the optional updates was for the HD4000 graphics. Now, in the past I have learned to not let windows update stuff like that as it invariably went wrong.

 So where do I start to get it all done correctly. Does it even matter what order I update them in? Thanks for any help as I really don't want to mess this up. Thanks.