Linksys-B? You means Linksys BEFW11S4, an wireless router with blue-black case and two antennas? Yes, it would work with DS lite. You need to config the WEP settings in router AND DS lite. Router WEP settings could be access from internet broswer or router software. It need to set WEP to use security key so hackers wont get in or use wireless internet without real user's permit.
Only way to access the WiFi settings in DS lite is though the WiFi games, not DS lite. WiFi games carry the blue circle with "Nintendo Wi-Fi Connection" on top-left of their DS cases.
Nintendo set up the website for WiFi games so players could get help or look for hot spots.
Nintendo WiFi's official website:
www.nintendowifi.com
and their customer support website:
http://www.nintendowifi.com/customersupport/SupportHome.jsp
And if you register your username to Nintendo WiFi then you could see who's top players demands how much scores they made.
You could access the WiFi hotspots at McDonald's anywhere. I once access the hotspot at Border's but not able to connect unless having accout from T-Mobile...