Many FSS topics are covered by these threads.

Reset of Maint. required message
http://www.peachparts.com/shopforum/showthread.php?t=257153

2006 320 Cdi
http://www.peachparts.com/shopforum/showthread.php?p=1344520

Flex Service Question
http://www.peachparts.com/shopforum/showthread.php?p=592181

Skipping Service A and B?
http://www.peachparts.com/shopforum/showthread.php?p=2087686

Changing oil & filter
http://www.peachparts.com/shopforum/showthread.php?p=1243250

Service B Reset
http://www.peachparts.com/shopforum/showthread.php?p=1842577

FSS cars, why do you have to use syn. oil
http://www.peachparts.com/shopforum/showthread.php?p=310927

FSS and Your Local MB Tech
http://www.peachparts.com/shopforum/showthread.php?p=82673

FSS Warning Message: Service in XX Days
http://www.peachparts.com/shopforum/showthread.php?p=1519603

Reset maintenance indicator S320
http://www.peachparts.com/shopforum/showthread.php?p=1416579

2007 GL450 Resetting Maintenance Service indicator
http://www.peachparts.com/shopforum/showthread.php?p=1563148

How does FSS work anyway?
http://www.peachparts.com/shopforum/showthread.php?p=485319

Wrench symbol in odometer?
http://www.peachparts.com/shopforum/showthread.php?p=245968

FSS resetting
http://www.peachparts.com/shopforum/showthread.php?p=729330

99 SLK 230 FSS Reset
http://www.peachparts.com/shopforum/showthread.php?p=88510

How to reset the FSS on 2008 Models
http://www.peachparts.com/shopforum/showthread.php?p=1948438

How do I cancel the message on odometer
http://www.peachparts.com/shopforum/showthread.php?p=591653

Resetting Service Light on a 210
http://www.peachparts.com/shopforum/showthread.php?p=1154658

Resetting the maintenance indicator 2007 C230
http://www.peachparts.com/shopforum/showthread.php?p=1935814

Reset the FSS (Little Wrench)?
http://www.peachparts.com/shopforum/showthread.php?p=750128

Resetting FSS + Cabin Air in 04 ML350
http://www.peachparts.com/shopforum/showthread.php?p=1586438

ML500 service message
http://www.peachparts.com/shopforum/showthread.php?p=2018584

Difficulty resetting "Service Due Now" on 99 Wagon
http://www.peachparts.com/shopforum/showthread.php?p=1299499

Service indicator reset?
http://www.peachparts.com/shopforum/showthread.php?p=160092