problems after installation

[Travis Newman]

> 1)    During installation I wasnt able to set my root(su) password, I 
> still don’t have it and I dont know how will make the modifications and 
> changes without su user and password.

Ubuntu doesn't use root by default. To perform admin tasks, use:
sudo command
which will prompt for your password, not the root password. This was 
done for simplicity and security reasons.

> 3)    It might be my mistake, but I fail to find where installation 
> files were, so i wasn’t able to choose which files to be installed or not.

That's because with the default install, it doesn't ask you. If you want 
a more detailed installation process, you can type "expert" and hit 
enter at the install cd boot instead of just hitting enter.

> 4)    Autodetection was fine, but I have almost never been asked how i 
> would like to set my hardware etc. I mean there was no advance mode 
> avaible.

Again, done for simplicity reasons. The Ubuntu devs want to keep it as 
simple as possible.

Most all of these questions are covered in depth in the wiki and the 
forums. Links to both are on the webpage.
http://www.ubuntulinux.org

I'll just hit the high points

> while booting it gave several error|fail messeges, i think it was due to 
> some of the hardware not detected(no suprise)

if its shpchp and pciehp, then don't worry about it.

> -    Unlike mandrake linux, it failed to mount my windows 
> partitions(well, hopefully I’ll able to manuel add them)

Yeah, you can. Covered in the wiki and on the forums, though I don't 
have an exact link. Search is your friend :)

> -    Music player fail to play my mp3, it gave an error like proper 
> plugins not installed and i dont know where to install additional 
> software(on suse there was YaST to deal with these kinda problems)

enable the universe and multiverse repositories (see instructions on the 
wiki and forums) and then:
sudo apt-get install gstreamer-mad
mp3 and many other codecs can not be included due to license restrictions.