I've set up an entry called NewFruitEntry that should be the template for all new fruits.
The editing is rather odd for WikiFruit to some but it is the same as on WikiPedia. The main thing that text formatting is done using string codes. For example:
''your text'' - the double ' makes italic
'''your text''' - the triple ' makes it bold
== is a second level heading
=== is a third level heading
There's a lot more out there but I think for now that's probably a good start.
We are currently trying/ planning to use the Wikimedia Commons for images (
http://commons.wikimedia.org/). This is the easiest place for us to store them. Please note that images placed there can be used by any other wiki in the world too.