Connecting Linksys Wireless G Router to ADSL Router/modem

Now – how could I connect a Linksys Wireless-G Broadband Router with Speedbooster to an already connected BT Voyager Wireless ADSL Modem? My reason for doing so is to get rid of a wired switch/hub currenly connecting 5 PC to the LAN. I wish to go wireless. replacing Hub/swicth with Linksys mentioned above and connecting to BT voyager Router/modem that is already connected to the internet. In all I wish to increase the range and getting at least 10 PCI wireless cards installed to allow share of Internet, files, printing etc.

Can this be done or am I asking for problems? Thanks for your reply.