Create and publish a form on Google Drive with a text field for each data item you want to capture (example).
Copy and paste the published google form url into the text field labelled 'ADD KEY' in the 'Tools' blok above and click the + button. Your form will be added to the blok stack on this page, click on the blok title to view and check your form.
Drag the generated link named 'Palmoto Bee' in the 'Tools' blok onto your browser bookmarks bar.
Visit any web page and click the new 'Palmoto Bee' bookmarklet on your bookmarks bar to inject your form and start capturing data.