the usual commands for updating your Raspbian installation

$ sudo raspi-config
…
$ sudo apt-get upgrade
$ sudo apt-get update

• http://shop.oreilly.com/product/0636920023371.do – Getting Started with Raspberry Pi
• http://shop.oreilly.com/product/0636920029595.do – RPi Cookbook
• http://shop.oreilly.com/product/0636920029083.do – RPi Hacks
• http://shop.oreilly.com/product/9781849694605.do – (PacktPub) RPi Networking Cookbook
• http://www.packtpub.com/raspberry-pi-networking-cookbook/book
• http://www.packtpub.com/raspberry-pi-media-center/book
• http://www.packtpub.com/raspberry-pi-server-essentials/book
• https://en.wikipedia.org/wiki/APT_(Debian)
• – the “Advanced Package Tool” for Debian