Adding images to the wiki is as simple as adding a url for an image from a content page. However, you should be careful that the image you are linking to is not copyrighted. You must assume that everything is copyrighted unless it contains a statement otherwise, e.g. a "creative commons" statement. We cannot take images to illustrate Camerapedia from other sites, scanned magazines or even manufacture's collateral. In fact, the only real way to be sure that an image is not copyrighted is to take it yourself.
To this end we have set up a flickr group for camerapedia. Flickr is free to join and post images to and they actively encourage users to link to their images from elsewhere. We encourage you to take photos of your own camera gear and collections and post the images to this flickr group.
Within flickr, if you click on "all sizes" you can select the image size appropriate to post on camerapedia and flickr will provide you with the url to use. You can then add this url to the camerapedia content page.
We will remove images when we encounter them if ownership and/or copyright cannot be verified. Any images posted the the flickr camerapedia group are considered fair game for use on camerapedia.