One of the things you should do when you first connect your Raspberry Pi to the internet is to run a system update to get the latest version of all the programs running on your Pi.
Programs in Raspbian are made up of a number of packages, updates to these packages are controlled by the Advanced Package Tool.
As you probably know it's easy to connect the Raspberry Pi to the internet using a network cable as it comes with a network connector built in. You just plug a cable into the connector on the Raspberry Pi and plug the other end into your router and it works. But how do you connect it to a wireless network?
So Raspbian is installed on the SD card and the SD card is in the card slot, what's next?
Before booting the Raspberry Pi for the first time, make sure you've got a keyboard and mouse plugged in and connected the monitor to the HDMI port.
Once you are ready, connect the power via the micro USB socket and it will boot up.
The Raspberry Pi doesn't come with a hard drive, instead it boots from an SD card. In order to install the operating system on the SD card you need to do what's known as flashing the SD card. To create a Raspbian SD card on a Windows system follow these instructions.