Mevans mentioned this in his post, but most people seem to ignore it, so I want to stress it once more. To make copying the texts into the mod much easier, please follow a few points on the format:

Plaintext

Use raw plaintext, not formated rich text.

To use plaintext in wiki/forum posts, you can use the <pre>(pre-formatted)</pre> tag to make it look like this:

#author:Bilbo Baggins
#title:The Song of Earendil
#types:rivendell,eriador,shire
Eärendil was a mariner
that tarried in Arvernien;
he built a boat of timber felled
in Nimbrethil to journey in;
her sails he wove of silver fair,
of silver were her lanterns made,
her prow was fashioned like a swan,
and light upon her banners laid.

You can also use the style attribute in the pre-tag like this:
<pre style="font-family:Calligraffitti"></pre>

#author: Bilbo Baggins
#title: The Song of Earendil
#types: rivendell,eriador,shire
Eärendil was a mariner
that tarried in Arvernien;
he built a boat of timber felled
in Nimbrethil to journey in;
her sails he wove of silver fair,
of silver were her lanterns made,
her prow was fashioned like a swan,
and light upon her banners laid.

The pre-tag does not automatically break too long lines. If your text contains very long lines (or you don't use newlines), use this style:

<pre style="white-space:pre-wrap; word-wrap:break-word;">

Add a header with metadata

Mevans has specified the following three meta-data headers:

1. title: The name of the generated book item
2. author: The author shown for the book ingame. May be empty.
3. types: The regions where the book can be found. See Mevans' post for a full list.

In your post you should at least give some thoughts about these points.

Provide a pastable text or file download

Mevens has used Pastebin for this in his examples. <pre>-tags are just as good. If you instead prefer to offer your files as download, make sure they have the correct encoding. Mevans didn't specify it explicitly, but I think UTF-8 encoding and Unix-style line endings are required.

As a final word, these are just recommendations to make your post be accepted more easily by Mevans. Your post doesn't have to be polished to perfection when you post it; others can help with fixing errors and formatting. But if your post stays in poor format, Mevans would have to edit your text all over to implement it and I can imagine that he would rather skip your text then.