If I may expand on G-Benz's suggestion.... when I first bought my W124 this summer, I spent a few hours reading some old messages on this forum. I even copied a number of messages that I thought would help later on. This exercise went a long way in getting me up to speed on how to maintain and repair my W124. Some of these archived messages even have pictures.
As usual, a manual always helps.
95 E320 Cabriolet, 131K