I know you have probably heard this already but the forum has about 10000 listings, so any help would be great.
I currently have a Linksys WRT54G, and the internet has come though fine for 2 year when it was wired. I recently got this laptop which has wireless built in, and since I got the laptop I have had nothing but problems. I keep getting people logging onto my connection, and IP conflictions happen far to frequent.
I would like to know how to secure my router properly, so those thieving buggers have to pay for their own high speed broadband!
Thank you, marl

use wpa

Not sure if your router has it like mine does but if it does you can limit access by MAC address. Basicly you enter the mac address of your laptop into the allow filter listing. Any other computer trying to connect that does not have that mac address will be blocked. I would also turn on WPA for extra security.

you can spoof a mac address, but wpa isnt crackable, so i would just go with wpa. not really a need to do both. you could do both, but its kind of overkill.

WPA not crackable? Uhm, not so sure about that. It can be done. I work as a computer tech, mostly on macs, but on my wireless network at home, I've got a wireless setup, and was using a 64 character hex password. Talked to a guy from dell, as I was having to deal with dell to get some machines that we have fixed under warranty, he said he could get into something like that in about 30 minutes. If someone wants in your network they can get into it. However, you can just make sure it's harder.

Try what other people have said, use the mac address filtering, also put wpa protection on the network.

Here...

https://www.grc.com/passwords.htm

This is supposed to generate you a 100% unique one time password for your network, you can make your own, but the stronger your password, the harder for someone to get into your network. Also, try disabling ssid broadcasting I think is what it's called....basically your network broadcasts that it's available and that it's there. You can disable that feature usually, then only the devices you have it configured for should know to search for it. You won't make your network 100% secure, not possible in my opinion. But you can make it hard enough for someone to get into it so that they'll move on to another target.