Combining 2 Different Joins

Hello,

I was wondering what is the best way to have multiple joins?

Here are the two statements I've been trying to combine
--------------------------------------------------------------------
SELECT CASE when
t1.Cust_DB_Shipment_Key = 'Used:' Then Description_1
Else (stuff(t1.Cust_DB_Shipment_Key,1,5,''))
End,
t1.Airway_Bill_No,
t1.Shipper_Reference,
t1.External_Product_Cd,
t1.Chargeable_Weight,
dt.CountTrackingNumber,
dt.SumProductCharge,
t1.Consignee_Company_Name,
CONVERT(CHAR(8),Ship_DT,112)
FROM Shipping t1
Inner Join
(
SELECT Cust_DB_Shipment_Key,
sum(PRODUCT_CHARGE_AMOUNT) as [SumProductCharge],
count(Airway_Bill_No) as [CountTrackingNumber]
FROM Shipping
Where Ship_DT = '2008-05-12' and status != 'voided'
GROUP BY Cust_DB_Shipment_Key
) dt
ON (stuff(t1.Cust_DB_Shipment_Key,1,5,'')) =
(stuff(dt.Cust_DB_Shipment_Key,1,5,''))
Where Ship_DT = '2008-05-12' and status != 'voided'

----------------------------------------------------------------------
SELECT CASE when
Cust_DB_Shipment_Key = 'Used:' Then Description_1
Else (stuff(Cust_DB_Shipment_Key,1,5,''))
End,
Airway_Bill_No,
Shipper_Reference,
Service_Name,
Chargeable_Weight,
Consignee_Company_Name,
CONVERT(CHAR(8),Ship_DT,112)
FROM Shipping
s JOIN Shipping..Distinct_Service_by_SAS_Code d ON s.External_Product_CD = d.SAS_Code
Where Ship_DT = '2008-05-12' and status != 'voided'

Thanks,

Stephen