what is wi-fi,is it free,user-friendlyneed to add something

Des.
Wi-Fi is the wireless system for you to though ethanet,
If you have the wire network at home but wants to change wireless,
You can buy one router and one client to share your network service.

Series and signal.
You can see N and G series wireless product in the market,
If your home indoor area less than 1000 square feet,
Than you take the G series is enough, and N for larger plan.

Connection.
eg. You have one desktop and one notebook,
First connect the ISP(PCCW, I-Cable, ect) LAN cable to router WAN port,
than connect port number 1 with cable to desktop to share wire service,
at last, install the wireless client( notebook can select PCMCIA or USB)
to recevied your wireless signal.

P.S:Dont forget to setup the wireless WEP password, it can protect your network