About releases:
How does a release look like

How does an original release look like?

The way a release is build up is in some ways dependent on what section it belongs to. Common, for all releases except music, is that the release (i.e. the game, program, movie etc.) is always archived in a number of RAR-archives. This has been done to facilitate the actual download of the release, and in some cases is also due to tradition.
A release always contains:

A main directory
All the files from a release are placed into 1 directory. The name of this directory is equal to the releasename.
There are certain rules concerning the releasenames. This is done so that all necessary information will be included in all releases. Uniformity creates a clear distinction - imagine if all groups would have their own ways of naming releases. This is also done to ensure the release on different kinds of platforms. Some of these can't cope with special letters, as å, ä, ö or blank spaces. To prevent the risk of getting an error only a certain set of symbols are allowed. These are:

ABCDEFGHIJKLMNOPQRSTUVWXYZ
abcdefghijklmnopqrstuvwxyz
0123456789-_.

SFV File SFV-file (.sfv)
SFV stands for Simple File Validator and is used to check files if they became corrupt after transfer. It does this by doing a CRC (cyclic redundancy check). After the check it displays which files contain CRC-errors and therefore are corrupt. It's also used on FTP servers / sites to check the progress of downloads or uploads.
NFO Info-file (.nfo)
A nfo file is a textfile with information about the release. The files are designed by ASCII artists and can be read with Damn NFO Viewer or simply with notepad. They contain release information like the runtime of a movie or an installation guide (if software).
WinRAR File WinRAR-file (.rar)
A rar file is a data compression archive format. The actual content is packed into a rar-archive. Ussually they are split to multiple rar volumes with a certain size (15 or 50 is standard). Scene releases are packed into rar files, but they are not compressed.

Not all types of releases are created in the same way. There are a lot of resemblances between them, but there are also some differences. Some are essential for that type or release, other things are the way their are because of tradition. Let's have a look at the individuel releasetypes:

MP3:
The mp3 releases are the only ones which aren't tagged into rar files.
Mp3 releases are tagged with _ to replace the spaces, instead of . with most types of releases.
Most mp3 releases contain .JPG scans of the front/back/inside covers of the cd.
Mp3 releases contain mp3 files, and also a m3u files.
m3u playlist m3u playlist file (.m3u)
A .m3u file basically is just a textfile that lists all mp3 files. If the .m3u file is loaded to a media player, the player plays the list of media files in the order they are listed in the playlist.

Movies - DVDr - TVRip:
These releases are all rarred. Most common, they are split into 15 mb rar files. For DVD5 50mb is standard, and for DVD9 100mb. These releases (can) contain:
Sample Vob A subfolder "Sample"
This folder contains a sample the movie. This way it's easy to check the quality of a release. The size of the sample is most of the time the same as the size per rar, so 50mb for a DVD5.
JPG Cover A subfolder "Cover"
This folder contains the scan(s) of the cover of the source, most common in .JPG format.
Subtitles A subfolder "Subs"
This folder contains the sub(s) of a movie. This is only for DiVX, XviD etc and not for DVD. The subtitle files are textfiles which can be loaded onto the movie, using programs like BS Player.
When a DVD is more than 1 disc, there are sub folders in the main folder: DISC1, DISC2 etc.. Same goes for CD: CD1, CD2 etc.

Games - Console Games - Apps:
Nothing new about this, they contain the .sfv file, .nfo file and the rar files.
Most games and applications are tagged with . and most console games are tagged with a _
0day apps are a little different though. Most of them don't contain a .SFV file, but a .diz file instead.
Also apps and games can contain subfolders like CD1/CD2.
.diz file file_id (.diz)
file_id.diz is a plain text file containing a brief content description of the archive in which it is included.

Next, some info about the tags (name of the releases).