To speak generally, you need to define a sidebar for your theme (sidebars contain widgets) and display that sidebar in your template.
- In your theme’s functions.php file, register a dynamic sidebar using
register_sidebar()
- Create a sidebar.php file in your theme directory that calls
dynamic_sidebar()
- Make sure your other template files (or header.php/footer.php if that is more appropriate) calls
get_sidebar()
If you need some more specifics, please feel free to update this question or ask a new question. (Seeing code is good, we can provide feedback on code.)