Well, yes, hacking WEP is not very complicated. We write about this on Maxi-Pedia in the IT&IS section. That is why you should enable
WPA or
WPA-PSK on your router instead of WEP.
How to make your wifi secure is a long story, so I suggest you look at the following links where they explain it quite well:
Wireless Wi-Fi network security tutorial 101 (part 1)
http://www.maxi-pedia.com/wireless+wifi+network+security+tutorial+101WPA and WPA2 (Wi-Fi security tutorial - part 2)
http://www.maxi-pedia.com/WPA+WPA2+WiFi+protected+accessIPSec, VPN, architecture (wireless security tutorial - part 3)
http://www.maxi-pedia.com/ipsec+vpn+wireless+architectureSecure your WLAN (wireless security tutorial - part 4)
http://www.maxi-pedia.com/other+wireless+security+WLAN+considerations