download
https://www.raspberrypi.org/downloads/raspbian/

verify sha256sum

65308c4a52cb2a6e7995c67e66aceca68a1b1944f2aacb1f89be55f4db9d48ab  2018-06-27-raspbian-stretch.img
8636ab9fdd8f58a8ec7dde33b83747696d31711d17ef68267dbbcd6cfb968c24  2018-06-27-raspbian-stretch.zip
1d1d85d0faa8211ca2be15b8777cf785000768f0115056673f55083281d081de  2018-06-27-raspbian-stretch.zip.torrent
85d9213eafd4982162306249100856491c51d304cf0faa5ee23306cee64effac  2018-06-27-raspbian-stretch-lite.img
3271b244734286d99aeba8fa043b6634cad488d211583814a2018fc14fdca313  2018-06-27-raspbian-stretch-lite.zip
a90c299df88198fc5b60c705d809f924a8a3f20eadd813c44c19abd900f6cd9c  2018-06-27-raspbian-stretch-lite.zip.torrent

flash sd card

dd if=2018-06-27-raspbian-stretch.img of=/dev/mmblk0 bs=1M

configure raspbian

sudo raspi-config

enable ssh, spi, serial, 1-wire, …

sudo touch /boot/ssh