How to culture bacteria?

So I have to culture E. coli for Biology cl but because of the procedure for this type of ignment I can't directly ask my teacher how I should do this (I need to use the internet to find out how). I know how to do it in nutrient agar but he told me to use broth for this one instead. I know I have to use a spectrophotometer to get my results but I have no idea how to do the actual culturing with the broth. And also, are there any special things I need to consider with the use of broth and using the spectro for this one?