You can link any page or form by tag Anchor
<a href="form2.aspx">Click Here To Visit Form 2</a>
or any page
<a href="page2.html">Click Here To Visit Page 2</a>
or you can use ASP.NET Controls like HyperLink
<asp:hyperlink id="HyperLink1" runat="server" navigateurl="form2.aspx" xmlns:asp="#unknown">HyperLink</asp:hyperlink>
in advance you could use Javascript plugins to make menu with motions and good user experience for example
http://jqueryui.com/menu/