If you're interested in purchasing either a paperback or hardback version of Sale's translation of the Qur'an, please consider a purchase at http://stores.lulu.com/store.php?fAcctID=1463778 .
At the time, Shoghi Effendi recommended this translation (and I think it can still be worthwhile, given especially the helpfulness (and readability) of the notes):
"As to the question raised by the Spiritual Assembly of Los Angeles concerning the best English translation of the Qur'an, the Guardian would recommend Sales' translation which is the most accurate rendering available, and is the most widespread."
(Shoghi Effendi, Directives of the Guardian, p. 63, emphasis added)
"It is certainly most difficult to thoroughly grasp all the Surihs of the Qur'án, as it requires a detailed knowledge of the social, religious and historical background of Arabia at the time of the appearance of the Prophet. The believers can not possibly hope, therefore, to understand the Surihs after the first or even second or third reading. They have to study them again and again, ponder over their meaning, with the help of certain commentaries and explanatory notes as found, for instance, in the admirable translation made by SALE, endeavor to acquire as clear and correct understanding of their meaning and import as possible...."
(On behalf of Shoghi Effendi, Directives of the Guardian, p. 64, emphasis added)
You would also be supporting the work of providing the digital files online here for free.