Installation
Simply unzip the release package, add your own content (described below) and if you are using an FTP package that allows drag and drop (File Zilla is recommended), drag the includes folder to the root directory on your site. The root directory is the one that contains your Admin, Images and Includes folders.
There are two main areas that you will want to customise: 1) the sidebox header and 2) the sidebox contents.
Customising the Header
To customise the header, open the includes/languages/english/extra_definitions/blank_sidebox_defines.php and replace the text that says Blank Sidebox Header. Take care to preserve the apostophes and if you want to include any apostrophes in your header then remember to escape them, i.e. put a backslash, "\" before them.
If you want the result to be available to any template, save it back to its current location.
If you want it to be available in a language other than English, save it to includes/languages/YOUR_LANGUAGE/extra_definitions/blank_sidebox_defines.php.
If you want it to be available only to your current template, save it to includes/languages/YOUR_LANGUAGE/extra_definitions/YOUR_TEMPLATE_NAME/blank_sidebox_defines.php.
Customising the Content
You can put virtually any HTML-based content you wish into your new sidebox, constrained only by your imagination and the space available. This includes text, images, links, buttons, forms, etc. There are examples in the files themselves that show the difference between simple textual additions for a monolingual site, and how to include text for multilingual sites.
If you wish your new sidebox to be available only for your current template, move the includes/modules/sideboxes/blank_sidebox.php file to includes/modules/sideboxes/YOUR_TEMPLATE_NAME/blank_sidebox.php
and includes/templates/template_default/sideboxes/tpl_blank_sidebox.php to includes/templates/YOUR_TEMPLATE_NAME/sideboxes/tpl_blank_sidebox.php
If you intend to use information from your database in your sidebox, then best practise would be to extract and manipulate the data in the blank_sidebox.php module file and place it in a variable or an array. Then use the data from this variable or array in the tpl_blank_sidebox.php template file.
Adding Several New Sideboxes
If you adding more than one new sidebox, you will need to do some renaming to avoid clashes. Simply replace all instances of blank_sidebox and BLANK_SIDEBOX in the files and the filenames with your preferred name e.g. logo_sidebox and LOGO_SIDEBOX.