Hooking wireless Laptop to the Linksys wireless router

I am so excited! My first laptop. I can’t figure out how to get it connected to the Internet. It is a wireless laptop. I have a desktop with a speedstream modem (DSL) and they are hooked to the Linksys router because I have a second desktop. Now I want to get on the Internet with my wireless laptop and I can’t figure out how to do it………….can anyone walk me through it?