You will need a contract with an Internet Service Provider (ISP)
You will need either a telephone line or a wired in cable providing internet services - 'phone line is more usual.
You will need a router - most people use wireless broadband routers which can operate with a hard-wired connection to several machines and (more usually) via a wireless connection to several machines. Up to six machines share one router in my house - all wireless.
Your computer will need a network communication device - often built in - to communicate with the router - either a Network card or a Wireless device. The hardware will also need a device driver - the software that makes it work.
You can navigate via Control Panel to Network Connections to see if you have either or both of these - if you see an Icon for Wireless then you have all you need in the laptop itself.
A contract with an ISP often comes with a "free" router. My contract in the UK with BT costs about £20 per month. There are cheaper offers.
Most but not all areas have the ability to provide Broadband connectivity.
If you are in the UK and select a Broadband supplier that is not BT be aware that if it's down the 'phone line then the supplier rents the equipment from BT as a sub contractor - this may give you a cheaper cost but if you have an issue then it can become frustrating when there's a technical problem or when you need to change anything.
If you already have the wireless router and an ISP contract then just navigate to Network Connections and turn on the wireless - right click on the Wireless Icon and select View Available Networks - you may see several of them - just connect to your router often the strongest signal.
http://www.bt.com/
Good luck...
Peccavi, October 2010
