Here's a helpful post.Can anyone simply tell me how you determine cover? I really don't get the pulling line things and the image in the book doesn't really clarify this for me..
See what squares people are in. See what squares the target(s) are in.
Pick a corner of the attacker's square. Draw a line from it to each corner of the target's square. If two or more of those lines are blocked then the target has cover. If three are blocked then the target has superior cover. If all are blocked then the target probably has total cover and can't be attacked, though there are a lot of possible exceptions to that last part.