When receiving PDFs via Gmail and saving them to Google Drive, many people download the file on to their PC first and then upload to Drive. There is however, a simpler way to save directly onto your Drive if you are a Chrome user.
From Gmail, click View to open a preview of the PDF. Click the print icon at the bottom right hand side of the doc, this will open up the Cloud Print screen. Under the Destination section on the left hand side you can select where to send your doc. In this instance you should click on the Change button and select Save to Google Drive. Finally, back at the Cloud Print screen press Save and the PDF will be saved in My Drive. The new PDF can then be found by sorting your My Drive by Last Modified and renamed as required.
Using this method, you can also save any web page to Google Drive as a PDF – click Ctrl-P to print from Google Chrome.
If you like the idea of saving web pages but want them to be images, try out the Save to Drive Chrome Extension – this will let you quickly save web pages – and images on websites – as PNG files at the click of a button.