To start using Translator Bookmarklet you need to head over to its main page. and choose your language and then drag the bookmarklet, as shown in the video, to your browser. Whenever you are reading a text that you want to translate , you just choose the laguage to which you want the content to be translated and there you go.
Translator Bookmarklet does not require any software download or registration. It is all free
Watch this video I made to learn how to use Translator Bookmarklet.