How do I get on a network??

I have no idea how 2 set up a network connection.. I'm alright at knowing what to do with computers.. Umm.. I have a laptop and computer both wirelessly and I was wondering how do I setup my own network connection for myself so that my computers are both protected from spyware,pop-ups,virus's, ect. My service provider is SBC..yahoo I have DSL modem..