Here are 2 resources that you might find very good.
http://www.mathsonline.org/pages/divisionSolution.html?1234&12&0&1
To do long division is a way to continuously divide 2 numbers until you get a repeating factor or you get an answer for instance 7/49 well 7^2=49 so that is a straight forward answer but if it was 7/49.9 you would use what you know on division and keep dividing and bringing down numbers until you get your answer.
Here are 2 resources that you might find very good.
http://www.mathsonline.org/pages/divisionSolution.html?1234&12&0&1