Some of the manga on this site is a mess. Here is some brief information to adding manga to the wiki.
Volume Naming
This is simple. Just because it Naruto Volume 5 doesn't make it a new volume. All manga of the same title should be under one volume, with the volume number as the issue number. Thus, Naruto volume 5 would be issue number 5 in a volume titled Naruto.
Publishers
I am well aware that copyright laws in Japan are different from the rest of the world. This means a manga can be released in Japan, nearly instantly translated into English and posted on the internet for anyone to read. This does not mean it has been released in English (or any other language for that matter). Look at the examples below:

Japanese

German

English
One is the original Japanese version. The others are reprints in other languages. Although they will have the same covers, the same art and virtually the same dialogue, they are considered different according to the wiki. They were published by different publishers or imprints at different times. They should not be considered the same.
This is true of nearly all manga, specifically those published by
Viz, an imprint of
Shueisha, the original Japanese publisher. Each should be a separate volume. The issue should only have that publishers cover and that publishers release date.
Dates
Manga generally do not have dates or indicias as other comics have. Usually, you will simply find the original publish date of the series. You may have to do some research to find when a specific volume was released.
Also, just as with other comics, nothing is to be added to the database until it is released. As said earlier, just because you can read it on a manga website doesn't mean it has been released for purchase yet.
Viz Media,
Del Ray and
Digital Manga Distributors, among others, have great websites to find when new volumes will be released.
Characters
Any manga character should be attached to all issues. Their first appearance should be attached to the original Japanese volume, not a translation. Also, while adding information to these character pages it should be noted that this is a comic site and we generally only consider manga to be the canon histories. Please make a separate section to notate anime information. We also have an excellent sister site known as
Anime Vice.
Conclusion
I think I covered the basic things that should be said. Having said them, I hope in the future that things can be cataloged correctly. I know there are some haters of manga on this site, but manga are comics and they belong here. Let's help this site become the biggest and best as far as both worlds are concerned.