How can I add thickness to a polygonal chain? I'm really new to blender and I'm trying to add thickness to a fairly complex polygonal chain. I've seen a lot on how to do it with Bezier curves but nothing on how to do it with polygonal chains. Does anybody know how to?

That orange dot in the middle is what I'm talking about the big mess on the left is my polygonal chain getting sucked towards it:



UPDATE: My problem was fixed thanks to this question and answer - line segments with edges into a curve
In Edit Mode select the whole mesh A, then press Alt+S to "Shrink or Fatten" the mesh by dragging the cursor.