Download the image from: https://www.raspberrypi.org/downloads/.

Use whichever method you are more comfortable with - NOOBS or RASPBIAN - to install and load the image onto a MicroSD card.

In my case I am using Raspbian Stretch Lite. Downloaded and unzipped the image, and then used the Disks utility in Ubuntu Linux to restore the image onto the SD card.

This step is only applicable to Raspberry Pi Zero W, as Pi 3 does not have a USB OTG port.

Additionally, if you have a monitor and keyboard connected to your Pi Zero W, you can also skip this step.

Otherwise, with your SD card plugged into the PC, modify/create the following files:

a) Go to the boot partition, open the config.txt file and add the following at the very end:

dtoverlay=dwc2

 b) Next, open the cmdline.txt file and add the following at the end of the line:

modules-load=dwc2,g_ether

 c) Create an empty file called ssh.

If you have a monitor and keyboard connected, simply log into the Pi with username pi and password raspberry.

Otherwise, if using Ethernet over USB emulation (Pi Zero W only), do the following:

a)  Make sure Avahi/Bonjour service is running. If you are on Mac or Linux, it most likely is. On Windows, download and install iTunes - it comes bundled with Bonjour.

b) Connect the Pi to your PC via USB cable. Use the USB port labelled "USB" on the Pi (not the "PWR IN" one).

c) Open a terminal application in your PC and log into the Pi using ssh (use PuTTY or similar on Windows):

ssh pi@raspberrypi.local

Password is the same as above. 

Execute raspi-config:

sudo raspi-config

a) Select option 1 and change your password.

b) Select option 4 and set your locale (I1), timezone (I2) and country (I4).

c) Reboot:

sudo reboot 

d) Log back in (see step 3).

To rid your system of "obsolete" :P networking packages, execute the following commands:

sudo apt remove --purge --auto-remove dhcpcd5 fake-hwclock ifupdown isc-dhcp-client isc-dhcp-common openresolv
sudo killall wpa_supplicant
sudo killall dhcpcd

a) Use your editor of choice (nano or vi) to create config file for the usb0 interface, e.g.:

sudo nano /etc/systemd/network/10-usb0.network

and enter the following in it:

[Match]
Name=usb0

[Network]
LinkLocalAddressing=ipv4

This will enable Link Local Address, aka APIPA (Automatic Private IP Addressing) on usb0.

b) Create config file for the wlan0 interface, e.g.:

sudo nano /etc/systemd/network/10-wlan0.network

with the following contents:

[Match]
Name=wlan0

[Network]
DHCP=ipv4

This will enable DHCP on wlan0.

c) Create config file for the eth0 interface:

sudo nano /etc/systemd/network/10-eth0.network

with the following contents:

[Match]
Name=eth0

[Network]
DHCP=ipv4

This will enable DHCP address on eth0. If you want to use a static IP address instead, replace the last line with:

Address=192.168.1.100/24
Gateway=192.168.1.1

or whatever your address, netmask and gateway are. 

Ref: https://systemd.network/systemd.network.html

a) Enable network management service:

sudo systemctl enable systemd-networkd

b) Enable network name resolution (DNS) service:

sudo ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf
sudo systemctl enable systemd-resolved

c) Enable network time synchronization (NTP) service:

sudo systemctl enable systemd-timesyncd

d) Reboot:

sudo reboot

e) Log back in (see step 3)

f) Check if everything is working:

systemctl status systemd-networkd
systemctl status systemd-resolved
systemctl status systemd-timesyncd

If you've made it thus far... well done. :)

a) Create config file to connect to your wireless network with Internet access:

sudo nano /etc/wpa_supplicant/wpa_supplicant-wlan0.conf

and enter the following in it:

ctrl_interface=DIR=/run/wpa_supplicant GROUP=netdev
update_config=0
country=US

network={
    ssid="name"
    psk="password"
}

Replace the country code with the same one you've chosen in step 4.

Replace the name and the password with the name and password of your wireless network.

You can enter several network={ ... } sections with different SSIDs one after another. wpa_supplicant will automatically connect to the network that's currently in range. Who needs NetworkManager, right? o.O

b) Secure your wireless config file:

sudo chmod 600 /etc/wpa_supplicant/wpa_supplicant-wlan0.conf

c) Enable and start wpa_supplicant on wlan0:

sudo systemctl enable wpa_supplicant@wlan0
sudo systemctl start wpa_supplicant@wlan0

d) Wait for it...

e) Wait for it...

f) OK, now check the status:

networkctl status wlan0

The wlan0 interface should be in configured state and have an IP address.

g) Try pinging something or someone, e.g.:

ping google.com

Ref: https://www.freebsd.org/cgi/man.cgi?wpa_supplicant.conf

sudo apt update
sudo apt dist-upgrade

One of the cool things about systemd is socket-based activation of services, wherein services are started and stopped on demand.

sudo systemctl enable ssh.socket
sudo systemctl start ssh.socket
sudo systemctl disable ssh.service
sudo systemctl stop ssh.service

If you are logged in via ssh, log out and back in:

exit
ssh pi@raspberrypi.local

Ref: http://0pointer.de/blog/projects/socket-activation.html