At the Post-Office

If you want to buy stamps, postcards, envelopes, to send a telegram or money order, to subscribe to newspapers or magazines, you have to go to the post-office.
At some post-offices there is a special window where you may pay your rent, telephone, gas and electricity bills.
Yesterday, I had to send a parcel to my friend in another city. So I went to the nearest post-office. I handed the package to the clerk at the window marked «Parcel Post». She weighed it and I paid for the stamps which she stuck on the package.
Then I went to the next window marked «Stamps». I had to queue up there. When my turn came, I bought writing paper, envelopes and a few stamps. I sat down at a desk and wrote a letter. When the letter was ready, I wrote the address on the envelope, stuck a stamp on it and dropped it into the nearest letter-box.

Questions:
1. Where do you have to go if you want to buy stamps, postcards, envelopes, to send a telegram or money order?
2. Where may you pay your rent, telephone, gas and electricity bills?
3. Where can you buy stamps and envelopes?
4. What is it necessary to do if you want to send a parcel to your friend?