You need to fill the DayPilotScheduler.Resources collection. It can be done either statically in the .aspx file or in the code behind (Page_Load).
Static loading:
<daypilot:daypilotscheduler runat="server" id="DayPilotScheduler1" ... >
<resources>
<daypilot:resource value="A" name="Room A"></daypilot:resource>
<daypilot:resource value="B" name="Room B"></daypilot:resource>
<daypilot:resource tooltip="Test" value="C" name="Room C"></daypilot:resource>
</resources>
</daypilot:daypilotscheduler>
Dynamic loading:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
DayPilotScheduler1.Resources.Add("Room A", "A");
DayPilotScheduler1.Resources.Add("Room B", "B");
DayPilotScheduler1.Resources.Add("Room C", "C");
}
// ...
}