Camera

Look for pictures, in text it is:

Look at the cable, find blue part, it must faces the USB ports.
CSI port is the nearest port to the USB ports;
If your camera not being connected to the cable, connectors side have to lay on the schema side;

sudo raspi-config
# Interfacing options -> camera -> enable
# Reboot

and reboot. OR enable it by editing config.txt, add in the 'all' section:

start_x=1
gpu_mem=256

Edit config.txt, add this in the 'all' section:

disable_camera_led=1

pi@raspberry:~ $ vcgencmd get_camera
supported=1 detected=1

If supported = 0, try updating firmware. If detected = 1 check camera connection.

sudo rpi-update

Simple get image to file:

raspistill -o cam.jpg

Horizontal and vertical flip image:

raspistill -vf -hf -o cam2.jpg