Avoid guessing about something. Only record an observation you are sure about.
Ask if you are not sure about something. You can post your question in the discussion comments under each article.
Avoid writing in the first person (e.g. I have found the bow to be effective when...).
Add wiki links as often as possible, just by putting double brackets around words you feel should have a page. Even if the page is not created yet and your link shows up red, someone will add the information eventually.
When creating a new page, try to keep the page name in singular form if possible. This is helpful because wiki links for many words can easily be extended from singular to plural form (e.g. entering [[pie]]s creates pies that links to pie), but the converse is not true.
When creating a new page, try to keep the page name in lower case unless the word is a proper noun. The first letter in a page name will automatically be capitalized by the wiki, but it will still accept lower case links (e.g. pie actually links to Pie). This is helpful because if a sentence contains many wiki links, the constant capitalization of first letters in a word can make it difficult to read. It also makes it easier to use parser functions  for various templates on the wiki.
If your page is missing a bit of information, please add it to the category Info Needed. To add a page to the category do the following:
View the page normally (not in edit mode)
Click the Add Category button (located in the center, at the end of the content of the page)
Type Info Needed into the box
Hit Enter on your keyboard
Click the SAVE button. That's it you're done!
This adds it to a list of pages that people can look at and see if they have the missing piece.
Do not create stubs or blank pages, only create pages if you have information to add.
Add pictures wherever possible! Pictures are pretty!