Can someone help?

First let me apologize. I am not a lawn care professional. I am your average Joe that is really clueless when it comes to lawncare. I didn't think this site was for professionals until after I signed up. I just took some pictures of my brown spotted lawn and uploaded them to my PC and was looking for some quick answers from people with knowledge and this is the first site I came upon.

Anywho, I'm sure most of you can answer my simple questions....

I first laid sod down in May, the lawn was great for the 1st month and then this happened and quickly spread throughout the yard. I don't know if this is a product of overwatering or grubs. I've been watering everyday (if not, every other) pretty much since I first laid the sod. But what is weird, if I was overwatering, the back of the yard would be brown too. So are these bugs attacking my lawn?

http://picasaweb.google.com/mxxxc3/BrownLawn

I'd appreciate any responses to how I can get rid of this problem and what I should use to get back that green grass!!

Thanks and sorry again.

Matt