If you just want to get the path to a certain action, use UrlHelper:
UrlHelper u = new UrlHelper(this.ControllerContext.RequestContext);
string url = u.Action("About", "Home", null);
if you want to create a hyperlink:
string link = HtmlHelper.GenerateLink(this.ControllerContext.RequestContext, System.Web.Routing.RouteTable.Routes, "My link", "Root", "About", "Home", null, null);
Intellisense will give you the meaning of each of the parameters.
Controller already has a UrlHelper:
string url = this.Url.Action("About", "Home", null);
Hope it is helpfull!!