How to edit/add one new field in checkout page?
I suggest this free extension link https://www.magentocommerce.com/magento-connect/easy-template-path-hints.html. It is approved by magento market place.
It will show path hints both blocks and templates for both frontend and backend.
After installed your module in your website. You can add this query string in the url ?tp=1&code=magento so it will show the path hints for that page.
Why i am suggesting this way, because when we using live site or development site. If u enabled the default magento path hints, it may affect the whole site. But if use this extension it will show only to your browsers.
Enable template path hints for Frontend
- Go to System -> Configuration.
- In the top left there is a box named “Current Configuration Scope“ which has a. drop down. From that drop down, choose your store view name.
- After this go to Advanced -> Developer->Debug And here make Template Path Hints = Yes.
Enable template path hints for Admin Panel
- Connect to database
- Enter values into 'core_config_data' table
Run the following query on the Magento database:
INSERT INTO core_config_data (scope, scope_id, path, value) VALUES ('websites', 0, 'dev/debug/template_hints', 1), ('websites', 0, 'dev/debug/template_hints_blocks', 1);
When you've finished development want to turn off template hints in the admin panel, open the core_config_data table and change the 'value' column of the two rows you inserted to "0".