I stopped reading after issue 7 and I want to know what happened since I left, I really wanna jump back into the series.

Well you should finish the story with #8 with Brainiac and the bottled city of Metropolis. Once thats done for the love of god you can skip issue #9. I don't even know why number 9 was even conceived so save yourself the time/energy/$3.99 and skip it. Issue #10 is really good and so on.

#8 just finishes the current arc. #9 is skippable but if you're interested in just keeping a collection I don't think it's a horrible issue, however it is pretty much just filler. #10 and 11 are the start of a new arc, you should pick up from 10.

I thought #9 was great. Just that it might seem a little outta place, but at the end of the day it'll probably tie in to a bigger story, Morrison wont write a story for nothing.

But you can still skip it.