I want to create a menu item in the left side pane with a text box and file browser included in it. I know how to create a simple addon. But couldnt understand how to create a menu item.
Open Text Editor then choose Templates->Python you will find templates for simple menus and panels (
Ui Simple Menu,
Ui Simple Panel), run them and see how it goes, they should give you a very good understanding of what you can do.
Running the UI Simple Panel will show it under the object properties as shown below, the location of the panel is specified using these three class parameters:
bl_space_type = 'PROPERTIES' bl_region_type = 'WINDOW' bl_context = "object"
To put in the left side you change the values as shown below: