What maintenance will I need to do to prevent any problems on 2005 Volvo S60

just bought this vehicle... and want to check for potential maintenance needs

Asked by for the 2005 Volvo S60
At the MINIMUM, you need to follow the manufacturers recommended maintenance schedule. On top of that, you need to get yourself a Volvo repair shop that knows what to watch for and follow their recommendations as far as any additional repairs or fluid maintenance that might be needed. This will make your car last for many miles/years!