My DS8 has gravitated to graphic novels. At home he's reading The Hatchet by Gary Paulson, but at school he's reading something called 'Bad Island'. He enjoys both.
I personally don't worry at this point about pushing his reading level. One thing I keep in mind is that most things (newspapers, magazines, novels) are written at about an 8th grade reading level for the general public. Our children are already at that level. I am more focused on him learning how to analyze what he's reading. To me that's what's going to help him, long-term, in school.
As for the homework, if it's boring, talk to the teacher about doing something different. DS has these worksheets, on Monday he reads a chapter then has to summarize it in about 2-3 sentances. Tuesday he has to read another chapter then write, in one sentence what happens at the beginning, the middle and the end. Wednesday is a Venn Diagram where he has to compare himself to a character. Thursday is a one-sentence summary, and then describe an event and how it reminded him of something he's seen/experienced/etc. I personally LOVE this homework as it's reading level independent. Plus, it's teaching him how to really look at what he's reading.
Anyway, I got off-topic, but I'd start with the teacher. In K my son's teacher went to the 1st grade teacher to get stuff for him. In 1st he was given 2nd grade stuff. Of course, the down-side to this method is that if you get a teacher who isn't into doing that extra work, you end up with a Very Bad Year(tm). Which is where we are at. He did 2nd grade work all last year, and is now being made to do it again.
