Came across this grass id pdf on the OSU turfgrass site. It's a bit technical, but the pictures are very good, and it is pretty straightforward. Click here for more information

In addition, the OSU site has a news and notes section that has some very interesting articles. Some you can ignore as they are geared more for professional turf managers, but others are very interesting. For instance, using Primo Maxx in the fall leads to early spring green up. You can pretty much screen which ones you want to read by the titles of the articles. Here's the link: Click here for more information