I always spell it as ‘Quran’. But I’ve seen a few variations on these boards, the most common being “Koran” and “Qu’ran”.
Is there a proper spelling for the name in English?
Depends what you mean by “proper”. Most dictionaries give more than one spelling, reflecting the difficulty of transliterating Arabic words into the Roman alphabet.
“Koran” used to be the common Anglicised spelling, but the fashion these days seems to be for more exotic looking spellings that better reflect the Arabic pronunciation. My dictionary gives Koran as the main spelling and Qur’an (note the glottal stop comes after the r) as a variant. If you want to be really picky you can spell it Qur’ān, with a macron over the a to indicate the long vowel.
In Arabic, if you have the right font, it’s ** ÇäâÑÂæ **.
To expand on that a bit, the above Arabic actually says “al-qur’an”, with al being the definite article (“the”).
So the first letter – reading from right to left of course – is an A ('alif, the vertical stroke on its own), then you have an L (lam, the next downstroke), a Q (qaf, the loop with two dots above), an R (ra’, the little hook that ends this ligature), then another A, this time with a little squiggle called a maddah above to indicate the glottal stop and long vowel, then a final N (nun, the u-shaped letter with a dot above).
Note than the U (or O) vowel is not normally shown. See how difficult it can be?
Disclaimer: I don’t know a whole lot about Arabic. Someone who does might tear that explanation to pieces.