Mobile Library Pt.1

Every three weeks the mobile library is coming comes to our village. The Mobile Library comes in a particularly for books converted bus that has been converted for books. When the bus halts and the visitors boarding the bus, the driver and librarian turns his seat. By doing this, he sits behind the counter. On both sites sides of the bus are shelves with books. On one site side are boxes. The boxes containing children´s books, board games, film DVDs, music CDs and audio books. The console games are under the control of the librarian (after?) the counter. Within the village's width of one km the bus stops three times.
Children, pupils and students pay no fees for lending. A single adult pays 18 €, a family card costs 25 € per year, but it is possible to pay per month if you like it or need to do so.
After boarding, the previous lent medias are returned, the loan period of not finished books will be extended if possible and new medias are requested.

In English nouns have a lower case letter unless it is a proper noun like Berlin or Fynn.

"Is coming" means that the bus is on its way right now; "comes" means it does it  regularly but not necessarily right now. This is the same with containing and boarding.

A "site" translates to Grundstück; the word you need is side.

Other than that, it is very good.