There's a new girl on the cover of volume 6 that isn't in OP/ED, I'm guessing that's when the anime ends.... We've just completed vol 4 with this week's episode so I guess... 2 episodes each for the remaining volumes?
For the record, I didn't read the novel yet, but for a simple story like this- with just a bit of background and pictures would pretty much tell you alot of what you need to know