R the Company has just released the new graphic version of the RoundCube manual. This is a manual discussing and depicting the generic version of RoundCube in 10 easy steps. This pictures might therefore be slightly different from the interface at your host, but the functions should be the same.
You can find the RoundCube manual here
This RoundCube howto is another manual in a whole series of new style manuals that R the Company will be bringing out over the next weeks. They will include chapters on Direct Admin, Joomla, WordPress, Plesk, WHCMS, Softaculous, RoundCube and Drupal to name but a few. If there are any specific wishes for a certain manual, please let us know, we might just agree and help you out with that.