This article hopes to improve the success rate of those who wish to engage with Wikipedia and maybe allay the fears of those who have not yet taken the plunge. I went to a workshop with representatives of museums, galleries and others in the cultural sector to hear from Wikipedia directly: what works and why. I won't go into full detail here but I would just like to make a few key points...
An article is actually a community. When you find an article on an area of interest to you, that article will often have a community and discussion board behind it. Introduce yourself to the community and ask if any help is needed. You may also find that some of the people there can help in your work...
If you have primary source material or there is detailed information on your organisation's site, you can add a link to it. Only add links where there is a reference to be followed or there is a great deal of extra information to be had. Gratuitous link adding can get people's backs up. On the other hand, useful external links to your website is great for your organisation.
Get involved with a WikiProject. There are projects concerning London, history and many other areas that could be relevant you. For example a botanist might go to WikiProject Plants - which is a place to collaborate and has an open call on more articles, taxonomic issues, photos and more.
If you wish to add a media item (photos, scans, video etc), you'll need to consider whether you are happy to release this into the public domain. If the copyright is with your organisation or someone else, you should not upload the item. If you own the copyright, decide whether you are happy to release it for free use into the world. You can license it so that you get attribution and that anyone building on your work must also make it freely available. You can also of course keep a higher resolution version that you release to anyone wishing to pay you.
Also, don’t copy and paste text from your organisation’s site or anywhere where it exists under a copyright notice. It will be removed from Wikipedia. By all means, rephrase, cite and comment on content though.
Edit as yourself, ie ‘John Doe’ not ‘Interpretation Team’. Wikipedia will blacklist you if you do!
Write from a neutral point of view, this doesn’t mean bland or avoiding controversy but rather that the reader of the piece would conclude that the author is not acting as an advocate for one side or the other.
These tips are directed at individuals rather an organisation. Your organisation may (or may not) develop a formal relationship with Wikipedia following the lead of institutions like the British Museum and this may affect the way you as an individual are encouraged to contribute in future. But if you have a lot to add on particular topics, there is nothing to stop you getting involved now.