In the server side, in order to retrieve the Resource detail using ResourceID you will need to iterate the Resources collection and match the ResourceID property. Here is the snippet to retrieve resource of an event in DataBound server side event handler using LINQ:

protected void WebScheduler1_DataBound(object sender, ISNet.WebUI.WebScheduler.WebSchedulerDataBoundDataArgs e)
{
    if (e.Type == WebSchedulerObjectType.Event)
    {
        WebSchedulerResource res = (WebSchedulerResource)
                (from r in WebScheduler1.Resources
                 where ((WebSchedulerResource)r).ResourceID == ((WebSchedulerEventBase)e.DataObject).ResourceID
                 select r).FirstOrDefault();

        //Process the resource object
    }
}

Unfortunately, WebScheduler do not provide any method to retrieve the resource using resource ID.