How do I make my wireless router secured?

I have already installed my wireless router and it is not secured, but now people around my house are logging on to my router.How do I make my wireless router secured?
Um put a password on the wireless network. And also change the admin passwords to log into the router config settings. If you cannot or do not know how then do please get someone to help you a VERY trusted person or even someone from your internet service provider to help you. This is important and needs done.How do I make my wireless router secured?
put a lock on it.
add a password right click properties on your driver.
on internet explorer type 192.168.2.1 then you will be able to pick WPA, WEP or WPA2. set password. then no one will be able to come in.put your username and password in safe spot.
Type 192.168.0.1 if it is dlink or 192.168.1.1 if it is linksys, netgear or SMC, in browser and go to wireless link and click on security. There you can secure it.
Google will find you a multi step procedure for doing that.