It is quite straightforward to setup a Raspberry Pi with Noobs. I added a wireless network adapter (USB) to the Raspberry. However, it will not work out of box, so I had to manually set it up.

Editing and configuring wpa_supplicant.conf was no help. I remember doing it in past but this time there were errors. So I did a quick fix in /etc/network/interfaces file

#allow-hotplug wlan0
#iface wlan0 inet manual
# wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

allow-hotplug wlan0
iface wlan0 inet dhcp
 wpa-ssid "SSID_OF_NETWORK"

Restart network: $ sudo ifup wlan0

This did the trick!

Just ensure, the power supply is good enough else it may lead to weird behavior.