Visual Site Designer allows you to insert guides to help you position page elements. Right-click the design area and select Insert Horizontal Guide or Insert Vertical Guide. This places a light blue guideline across the page that you can move using your mouse. By using multiple guides, you can easily create organized layouts. You can also enable a grid by navigating to View > Grid and selecting one of the provided sizes. (1x is the smallest, and 4x is the largest.)
You can also access an option to evenly space the selected element(s) between two guides by right-clicking the page and selecting Space Evenly > Between Horizontal/Vertical Guides.
To move objects with more precision, you can use the arrow keys to nudge objects pixel-by-pixel around your page.