How you log into the Raspberry Pi differs depending on if you set it up with a screen and keyboard, or if you access it remotely.

With screen and keyboard connected

To access the Raspberry Pi with a screen and keyboard connected, boot it up and log in with the user name pi and the password raspberry.

To determine the IP address of the Raspberry Pi, open a terminal on the Raspberry Pi and type hostname -I.

Remote connection

To access the Raspberry Pi remotely, you must use an SSH client. To copy files to the Raspberry Pi, you need the SCP file transfer program. Both programs must be installed on your computer. If your computer runs on Linux or Mac OS, the programs are most likely installed already. If not, install ssh and scp. On Windows, you can for example install PuTTY and PSCP.

To connect to the Raspberry Pi from your computer, you must first determine the IP address of the Raspberry Pi. See http://www.raspberrypi.org/documentation/troubleshooting/hardware/networking/ip-address.md for several options on how to find the IP address that has been assigned to the Raspberry Pi. If none of these work for you, you must temporarily assign a static network address to the Raspberry Pi.

When you know which IP address is assigned to the Raspberry Pi, you can use ssh to log into the Raspberry Pi with the user name pi and the password raspberry: ssh -l pi IP_address

Advanced: Assigning a static IP

In most cases, you can figure out the Raspberry Pi's IP address, so that you do not need to assign a static address. If you must assign a static IP address, power down the Raspberry Pi, remove the SD card, and insert it into the SD card reader of your computer (note that this procedure works only on Linux or Mac OS computers). Navigate to the file /etc/network/interfaces on the SD card and open it in a text editor. Add a static network, for example:

auto eth0:1
iface eth0:1 inet static
address 192.168.111.111
netmask 255.255.255.0

Next, put the SD card into the Raspberry Pi again. Couple the Raspberry Pi to your computer with a network cable and configure your computer to use the same static network as the Raspberry Pi. For example, assign the computer the IP 192.168.111.112 with the same netmask that you used for the Raspberry Pi. If your computer runs on Linux, issue the following command, for example:

sudo ifconfig eth0 192.168.111.112 netmask 255.255.255.0