Gnomebaker is nice, but I understand that at the moment K3b is the most 'mature' cd/dvd burning application on Linux. One might need to manually get the mp3 decoder plugin for it if the distribution doesn't ship with one (for the same reasons why mp3 player plugins might be missing at first), but after that you can burn (along with other formats) mp3 music as regular audio discs, for example.
I don't think there's any use trying to get Nero working under Linux, especially if no native installer exists, since K3b provides everything a cd/dvd writing tool should. Of course it uses the same (command-line) programs to do the job that the other front-ends do (I believe gnomebaker too), but it's graphical interface is way better than on any other I've seen.
Real command-line commandos, however, always do it using the command-line tools