The relative clause is communicatively very important and it is being used frequently. It is quite simple to build, you just need to use relative pronouns (see the table) as conjunction. As you can see, the relative conjunction looks almost the same as the definite article (except for the Genitive: dessen, deren/derer).

The word order in this clause is the same as in any other subordinate clause: Das ist der Taxifrahrer, der mich zum Flughafen begracht hat. 

However there is something that needs to be considered – the correct use of the Genitive Plural. Take a look at these two sentences and try to remember them as good examples for both scenarios:

Das sind die Eltern, deren Kinder nach Deutschland fahren.

Das war die Leistung derer, die verantwortlich sind. (=>derer comes always in the combination derer, die).