The chart below shows how I service my own bike. My service chart is a mix of the factory's directions and my own experiences. I drive approx. 10.000 km's a year.

Service	Interval	Comments
Change engine oil	3000 km	Agip 10-40
Change oil filter	6000 km	Because its external on my bike - if it vas internal as with the standard setup, I guess I would only change it once a year.
Change gear oil	Once a year	80/90
Change bevel box oil	Once a year	230mL 80/90 oil + 20mL Molycote. The thread in the level plug hole in the bevel box is VERY easily destroyed. Leave it in place, and pour in the correct quantity from a measuring cup.
Adjust valve clearance	6000 km	.
Syncing carbs	6000 km	My bike has a special setup with very short carb cables that keeps in sync for a long time. For a standard bike with the long cables I guess I would synchronize the carbs every 3000 km.
Clean Air filters (K&N)	Once a year	I have no idea about service interval for original filters. Check the manual.
Empty float chambers	3000 km	Especially important if you are driving with velocity stacks og K&N type filters.
Adjust ignition	-	No need with electronic ignition, with the ordinary contact breaker ignition, I'll suggest a check for every 3000 km.
Change spark plugs	Once a year	.
Change fork oil	Every 2 years	Fork oil on a Moto Guzzi has no damping function, its only there for lubrication and for anti corrosion purpose. So it's not critical.
Water on the battery	Once a year	- or if the bike does not behave like its supposed to :-)

I always carry a small stock of the most common service parts to be free to decide when to service my bike:

Engine oil
Oil filters
Gearbox oil
Molykote for the bevel box
Valve cover gaskets
Gaskets for the oil sump
Spark plugs
Clutch cable
Gas cables
Rev counter cable