Adding a web resource style sheet to a web server control

I've created a web server control and want to embed the style sheet within it.

In my AddResource function, I have:
                url = Page.ClientScript.GetWebResourceUrl(t, "stylesheet.css")

In my assemblyinfo.vb I have:
<Assembly: System.Web.UI.WebResource("stylesheet.css", "text/css")>

The stylesheet is within this path within the web control project:
/resources/styles/stylesheet.css

How do I access it? It isn't finding the styles.
I've tried adding the paths:

<Assembly: System.Web.UI.WebResource("/Resources/Styles/stylesheet.css", "text/css")>

How do I do this?

thanks.