While this concept is very highly dependent on personal preference(see 1TBS for comparison), the concept and importantce of some sort of standard is worth emphasizing. Even if you choose your own file naming convention, there are a few elements that really should be followed.
Artist name before Song Title: If indeed you even bother to put the artist name on the filename, please put it before the song name. After all, record stores don't organize CDs based on the alphabetical order of the song titles.
Periods considered harmful: one or two rare individuals decided to be '1337' and use a '.' as their field delimiter (i.e. "artist.title.mp3"). This is a Bad Thing, since it is generally accepted that the period character is unofficially reserved for information about the format of the file in question ("*.tar.gz", for example). So, then, the use of the period character IS generally acceptable if the additional information is valuable in telling more about the file structure -- a friend of mine uses "artist - album - track - title.196kbps.44khz.joint.mp3". It's certainly long-winded, but useful... if you're into that sort of thing.
I don't give a pair of fettered dingoes kidneys who 'released' it: There are groups of 'l337 d00dz on the net who spend all their time 'releaseing' CDs. Oftentimes, they will append the TLA of their group on the end of the filename.Okay, this needs clarification for those who don't get what I am saying. Put your name in there all you like, just not in the filename. There is a reason .nfo/.svf/.diz files and ID3 tags exist. Removed because of the highly subjective nature of the point being made.
Be aware of reserved characters: Please, never assume that everyone on every OS can escape the same characters you can. In many OSs, characters like '*' and '?' are perfectly valid in filenames, and in others they are not, and must be escaped. In still others, they cannot be escaped and can cause problems.
The only character where allowances for this are made is whitespace, eg 'space bar'. This is a very valuable character and it is generally accepted that any OS worth it's cache can handle them (though many intrepid souls still insist on using underscores versus whitespace).
Fill in the ID3(-2) Tags - That's what they're there for. If you go through all the effort of naming your files intelligently and yet don't do the ID3 (or ID3-2) part, you're just wasting a valuable standard. Most programs that do the ripping and encoding in house can use CDDB to get all the information you need to make your ID3 tags meaningful.
ID3 is especially important if I don't like your filename naming scheme. There are more then 10 programs I know off-hand that will parse a list of files and rename them based on their ID3 Info, so if I want them renamed some other way, I can change it programmatically, and that makes me a happy boy.
* whew * That turned into a bit of a rant ** RANT **. To be fair, though , let us see what the populous thinks of what the One True MP3 Filename Format is... Hmm, according to several random searched on ye' olde' random P2P server, the proletariat(sp) thinks it should be:
artist - title.mp3
coming in second place and
artist - album - track - title.mp3
Coming in third.
CrowJane says Amazingly enough, quite a bit of technology used today doesn't support long file names; either because there is no 'standard' filesystem, or just laziness. MacOS 9 and lower halt at 31 characters (IIRC), we all know about MS-DOS (8.3 character filenames) and many MP3 Players (both solid-state and CD-based) cannot do long filenames. Just make sure you've got your ID3's in there, too, and everyone *should* be happy :)