You say you followed the instructions, & you've managed to get online.
So why do you think you haven't set it up properly?
And you "don't think you're safe"?
FAQ for the router:
http://www.voyager.bt.com/faqs/wirel...xp/2100faq.htm
Article about securing a wireless network:
http://www.cableforum.co.uk/board/article.php?a=12