WiFi Wardware required

Hi ppl!! planning to go wifi.. so i was there at bestbuy but got confused about what to buy(i am soo far from my digit mag!!)

i have a plug and play CAT5 based internet supply(16Mbps/8MBps) and a wifi laptop. please suggest the recommended hardware.

As i have a hi speed broadband, i dont wanna loose on the speed.

thanks..