Right so the first thing you want is to change your site hierarchy to this:
Home
|-- About Us
|-- Contact Us
|-- Services
You can find in Document Types, under Settings in the home node'S document type, the Structure tab to add the allowed node children node types to make the home node have allowed children of the 3 types you have.
Next you'll want this code to reach your home node:
var homeNode = Model.Content.AncestorOrSelf("Site");
Where "Site" is your home node's document type.
Next you can prepare the data you'll want to loop:
var menuItems = homeNode.children.Where(x => x.IsVisible());
Finally you can change your loop to this:
@foreach (var page in menuItems)
This should help you get this to work.