kimtech, check the service provider(ISP) for whather they provide Wireless Routers(cum ADSL modem) or not. If yes simply buy/rent the Wireles router from them. You dont need anything else for accessing internet.
If your ISP is cable based(like sify or Hathway) buy Linksys WRT54G2 or Netgear or <search in the forum for Wi-Fi router> buy it and configure(for security) and use it.
If your ISP is cable based(like sify or Hathway) buy Linksys WRT54G2 or Netgear or <search in the forum for Wi-Fi router> buy it and configure(for security) and use it.