If you are having your car serviced by a garage be it by Mercedes Independent or Mercedes Main Dealer then they will be aware of the procedures to follow and what is checked when.
However if you are doing your own servicing and many owners now prefer to do so, there is little doubt it is cheaper after you have bought the necessary tools, and is also more convenient in that you can to the various checks in stages and spread the cost and you do not loose out in the use of your car along with the hassle of getting the car to and from the garage.
Albeit some garages will now pick the car up and drop it back to you at home or work. BUT be prepared to pay!
If doing your own serving then following the lists for the A & B service in the W168 section of this site Page 47, that will ensure you cover all the necessary points. There being very little difference between the w168 and w169 models accept top say that in a number of cases the serving on the W169 is far easier than on the W168. Changing the carbon filter is one example, on the W168 it can take 30 mins or more whereas on the W169 in takes only a few minutes.
Making sure that you do cover the servicing of any extra's fitted to the car, such as Eco start Battery, and tow bar fixtures and fittings which does now come within the MOT.(Ministry of transport Test) required in the UK Annually after the 3rd year.
If you are driving an automatic then ensure the transmission fluid is changed at the prescribed intervals as set out in your hand book or as advised by a service centre.
Many owners request the procedures for re-setting the assyst, I would point out that this should never be re-set until such times as the service schedule is complete, to do so creates a false sense of security where upon your car may be unsafe, or more likely to breakdown
Changing the service data on your car does not make the brake pads last longer, anymore than an air filter becomes clean, so if altering the servicing data which enhances your safety as well as other road users and pedestrians.
The re-set assyst procedures for the w169 are currently on My DVD along with the variations that can arise, I will add them to this page in due course.