Shrink layer to shape

[infiniteWin]

I had an old logo which I traced over (text and rectangles). I created a new layer for each rectangle as I wanted to align the shapes later. I've since found out that guides work on layers, not the shapes in them, and was hoping on some advice on what to do as a don't see a resize to contents option for layers or a way to get the shapes, not layers, to snap to guides.

Any help would be apreciated