1) Buy a wireless router - some organisations provide this for free when you sign up for their ISP services.
2) Buy and install a wireless device into your computer - hardware and the software device driver that makes it work.
3) Connect wireless router to 'phone line through a filter and connect 'phone through filter too.
4) Switch it all on
5) On computer navigate to network connections and see if the wireless card can "see" your router - a right click on the wireless icon - view available wireless networks - connect to your router.
6) Fire up a web browser - Internet (spit) Explorer
That's all... 20 mins to half an hour...
The Router handles the Internet down the 'phone line - the wireless card in your computer handles the local network between the computer and the router - all you have to do is install the H/W & S/W and set up the network link.
If it doesn't work get on the 'phone to the call centre and a nice Indian person in Bangalore will help you out - they are very patient, knowledgeable and helpful.
Good luck...
Peccavi, May 2009