Quark uses a 12 Column grid to display its content. By default, it uses 8 columns for the main body content and 4 columns for the sidebar.
If you want to display both a left and right sidebar, then you’ll need to change each of the templates to use a different number of columns. I would suggest, 3-6-3. (ie. 3 columns for each sidebar and 6 columns for the main content).
If you look in index.php you’ll see something along the following lines…
You’d need to change this to the number of columns you want to use. eg…
You need to do the same to sidebar.php to change the columns from 4 to 3 (or whatever you want to use for the right sidebar).
For your own left sidebar template, you’d need to add the div containing the relevant number of columns, just like sidebar.php.
You’ll need to do this for all the template files (eg. page.php, single.php etc..).
Also, you need to remember that the total of all your columns must equal 12, otherwise you’ll end up with issues.