I run my blog at www.stockhola.com I am trying to add a button or some of my own code to the left hand menu but every time i do it screws up the entire web site. Any ideas why? I dont have a left_column.php file or anything like that.
You dont have a left-coloum.php in wordpress. You must have a sidebar.php Just edit it in correct way and introduce your codes there. It must work then. If you are still facing some problems,thn i an do it for you. PM me.
The default is called sidebar.php but it isn't always the case. At one point my blog had 2 sidebars so I called one sidebar-left.php and one sidebar-right.php (how original eh!). You can call it what you want as long as you link to it correctly. You are right in this instance though From the source the left sidebar has an id sidebar so it's likely this is the name of the template too. stockhola - what button are you adding thats causing problem?
Just elaborating a little on Jooma Dude's answer... It may also be called something else like left-sidebar.php, although sidebar.php is the common name people use. The file will be in wp-content/themes/yourtheme/