are you in X yet?(graphic user interface), or command line(terminal screen with prompt)?
if youve got a GUI in front of you start looking in the menu, I believe Mandrake has graphic setup aids to do all this.You may have to log in as root or it might let you sudo to it within the GUI, KDE GUI will for sure, it will ask you for it for system changes.
X not working yet:
get it working, find your video card chipset, then while logged in as root type xorgconfig, or xf86config and follow the prompts, if youve got an nvidia or ati card select a generic driver and then get one later when on the net.after that type startx and start looking for a menu.
oh ya, if your in command line(x isnt working) not sure about a command typing the first few letters then tab key will complete it for you or list the possibilities, for example xorgconfig might not be exactly that, typing xorg<tabkey> witll spit out what your looking for if it exists.
what kind of connection, cable?if so, dhcp or static ip?
Dial up?, is modem linux compatitble?