Hello Soj,
You should be able to add features such as a left-hand sidebar without knowledge of PHP, although you'll need to know CSS and, of course, HTML. OJS uses the Smarty template system to separate content from code; see the Smarty website (
http://smarty.php.net) for more information.
The tricky part will be determining which template is being displayed if you want to modify a specific page. To find the handling code, see the OJS Technical Reference (
http://pkp.sfu.ca/ojs/OJSTechnicalReference.pdf) on page 10-11; the last function call in the handling code will most often indicate the template being used.
If you'd like to add a left-hand sidebar throughout the site, templates/common/header.tpl is the best template to change. I'd suggest putting your additional code in a separate template file and using a Smarty {include file="..."} call in header.tpl to bring it in. This will make OJS upgrades easier.
Regards,
Alec Smecher
Open Journal Systems Team