how to put protection on a router for my computer

[brodkill]

i just set up wi-fi on my computer so that i can have internet on my wii. i can not figure out how to put security on my wi-fi connection

i am using a d-link router

i was told by a friend that all i needed to do was put my ip address in my web browser search par and go from there, but that does not work for me

if anybody knows a really easy/simple way of puting security on a d-link roter, i'd love for you to help me