I recommend the five part video series on the Islamic State over on VICE News. Very factual with a minimum of ‘interpretation’. VICE News is often a haven of fluorescent idiocy and tedious Guardian-speak, but in this case it has been a while since I have seen such good old fashioned journalism relating to the Middle East.
UPDATE: they have posted the series in one full length video, so I have adjusted the link accordingly. Highly recommended.