Hide any control in master page for example site actions

In order to hide site actions ribbon you can use spsecuritytrimmedcontrol in master page.

<SharePoint:SPSecurityTrimmedControl ID=”SPSecurityTrimmedControl1″
  PermissionsString=”manageLists” runat=”server”>

hidden controls for users who do not have managelists permission

</SharePoint:SPSecurityTrimmedControl> 

rate topsharepoint sites

If you would like to get some rating for your internet facing sites
visit
www.wssdemo.com

www.topsharepoint.com

override core css in sharepoint

If you would like to override any core sharepoint css in your own custom css just use !important tag for the css in your custom css and it will override the outofbox css!!
example-
your custom css

.ws-body
{
background-color:red!important;
}