I know two ways to email a webpage or a link to a webpage. 1. When on a webpage click on the Firefiox button at the top left of your screen - on the drop down list click on Email Link... then on my Windows 8 system I click on windows mail, select who I am sending it to and send it. 2. While composing an email I can type in, for example, www.mozilla.org/en-US/firefox/mobile/platforms/ which I find on whatever webpage I am on. The address is automatically a different color (blue) in my email. If the receiver clicks on this link they will be automatically be taken to the webpage. The second method is more labor intensive, both methods do exactly the same thing so I recommend the first method. Send me a reply if I can assist you further.

You can install an add-on such as https://addons.mozilla.org/en-US/firefox/addon/email-this to easily email a link.

The extension mentioned above might be the easiest solution, but there also is a built-in feature on the menu:

orange Firefox button (or File menu) > Email Link...

However, you need to inform Firefox about your preferred email program or webmail site before you can use this feature. This article has some tips on that: Change the program used to open email links. Depending on your account type, this may be quite easy or involves multiple steps.