I'm not exactly sure how to line things up either, but I'll bump this for ya because I was going to ask a similar question.
How would I align the boxes perfectly on the dotted line to the left?
There has to be some way to "snap to" the line rather than having to manually move them until they appear to be lined up. I just haven't fiddled with it enough...I need to use it for a project I have at work though.