list of installed packages

["dokdokLUG" <chadi@cebu.pworld.net.ph>]

hi and good day everyone !!!
  when installing debian2 , i chose some of the preselected packages that the installer program suggested, now, can someone pls direct as to where i may find a complete list of the files that has been installed to my system and where ?
  also, when i use dpkg -i filename.deb to install a package, is it also possible for me to get a complete list of all the files that the dpkg program added and those config files w/c she mage changes to ?

thanks a lot,
from the NewbieLinuxUsersGroup in Cebu City Philippines