How could i update the gcc? Also how can i install MPlayer+Open office, the latest versions??

apt-get update

apt-get install mplayer
apt-get install openoffice

The first answer I gave will update your entire system, which is usually a good idea. I don't know if the latter two answers will work, just a guess at their .deb names. If they don't work, try a few different names.

This is a prime target for an RTFM, so make sure you read the FAQ and check out APT

Reading is fun.

No, the apt-get update command just check the repositories and scans the index files. The command you're looking for it apt-get upgrade. Mplayer is better to install from source. Most of the precompiled packages are crippled. To install openoffice you type apt-get install openoffice.org openoffice.org-help. You'll have to be at least in testing to do this. Stable has no openoffice package. As for gcc, you can type apt-get install gcc and if there's a newer version available in that distro (stable testing or unstable) then it will download it for you. If it says gcc is already the newest version, you'll have to upgrade to a newer distro and make sure you've done an apt-get update. One note about gcc. If you're compiling programs (like mplayer, for example) use gcc-2.95. Version 3.3 can make slightly dodgy programs. I found this out the hard way when I couldn't get X to start. Recompiled the driver with gcc-2.95 and presto.

You can also use synaptic. It has an upgrade button when you select packages that are installed. If you can't find packages in the official repositories you can check out the unofficial ones at apt-get.org.

if you use either apt-get upgrade or apt-get dist-upgrade I suggest using the "-u" (apt-get -u upgrade) option to list the packages that are going to be upgraded.