Use a micro SD card and connect it to your pc (MAC OSX). Check the mount point for the SD card RPI install docs

diskutil list

#=> 
#/dev/disk1
#:                       TYPE NAME                    SIZE       IDENTIFIER
#0:     FDisk_partition_scheme                        *8.0 GB     disk1
#1:             Windows_FAT_32 boot                    66.1 MB    disk1s1
#2:                      Linux                         7.9 GB     disk1s2

Unmount the SD card but do not eject it!

diskutil unmountDisk /dev/disk1
#=> Unmount of all volumes on disk1 was successful

Install the image (Get the image for RPI Jessie Lite)

sudo dd bs=1m if=Downloads/2016-05-27-raspbian-jessie-lite.img of=/dev/disk1
#1323+0 records in
#1323+0 records out
#1387266048 bytes transferred in 1061.956414 secs (1306330 bytes/sec)

Boot up the raspberry PI with the SD card and connect the ethernet cable to your home router. Find the IP assigned to the RPI:

nmap -sP 192.168.0.1/24

SSH to your RPI by using the default uname/passwd

ssh pi@192.168.0.? 
#=> password: raspberry

Extend the RPI filesystem to cover the whole SD card, and reboot

sudo raspi-config

If you have a wifi dongle attached to the RPI then

sudo iwlist wlan0 scan
sudo vi /etc/wpa_supplicant/wpa_supplicant.conf

And add the following lines at the bottom

network={
    ssid="The_ESSID_from_earlier"
    psk="Your_wifi_password"
}

Continue with installing python3 and pip3, git

sudo apt-get update
sudo apt-get install python3
sudo apt-get install python3-pip
sudo apt-get install git