The ARRSEPedia is a Wiki, just like wikipedia, but for the British Army / ARRSE and not quite 100% serious. The ARRSEPedia is a mass of articles that anyone can create or Edit. The idea is that if everyone contributes a little of his knowledge, opinions, sense of humour and experience then something really impressive... the ARRSEPedia.. is created.
The most important thing is that you or anyone else can contribute immediately with no interference. You can start new pages or edit existing ones. If you'd like to share your knowledge of Rations, feel free. We would all just love to know about Satellites for example. What about your experience of operations or knowledge of Places and Postings? Anything in fact - in short, get writing, although do please have a look at the site policy before posting though.
Why don't you start by browsing using the Random Article page - try it a few times (link is on the menu to the left), and see what you come up with. To be a bit more organised about it try the Help pages or the Tutorial pages. This should explain a bit more about the ARRSEpedia and get you started with adding your own content.