Get started with Foundation Sass in Visual Studio
Install the "Web Essentials" visual studio extension
(Tools > Extensions & Updates > Online > Search for "Web Essentials") It can compile scss to css. It also has css preview in the scss editor.
Don't ever install or depend on Web Essentials. It's prematurely released with bugs, upgrades not compatible etc. It's just messy and I will never ever depend on WE again.
Get Foundation Scss
Foundation is distributed through the "Bower" extension manager. Instead of using that (it's not very MS/VS at all) just download the Foundation scss files directly from the git repo hosting the "Foundation Bower Package" which is updated from the "Foundation" git repo. Go to https://github.com/zurb/bower-foundation and [Download as Zip]. Place the .scss files in the "content/css/foundation" directory of your solution.