I've created a new inline type and i get an error message about 'could not fine inline handler'

For .net sites, you will need to edit the web.config file to recognise the new inline. For coldfusion sites, you will need to edit act_arrayofparagraphs.cfm and act_media.cfm. For java sites you will need to modify the iCM4j media and inline plugins. Refer to the attached documentation reference section for the files to modify.

Image icons suitable for use will already exist in your images/media folder.  The files reflect the logo for the recommended program used to open the media, so for csv media types which open in excel, you can copy and rename the xlsicon.gif that already exists; for RTF or docx files, use the wordicon.gif in the same way.