Most of the time, you must stop your contracts (water, electricity, telephone,
rent, TV,) by sending a letter. If you paid your bills by standing order, don't
forget to tell your bank. As you needed to complete forms when you left, you
will need to fill in forms when you return.
The easiest way is to contact the consulate where you are registered to sort
out your situation. You will have to establish a fully detailed inventory of
your furniture.
A moving form attestation is often demanded when you pass the border (you
can ask for it at your Consulate).
You will have to think about school registration if you have children.