Making things just a bit easier, the Presentation application in Google Docs now has a snap to grid feature and it is turned on by default.  Snap to grid makes it easy to auto-align text, images, shapes, and tables within your slides. 

But, there's more than meets the eye with snap to grid. Try out these handy keyboard modifiers: 

[ALT] while dragging turns off the grid and gives you smooth drag (use [OPTION] on a mac)

[SHIFT] while dragging enables vertical and horizontal dragging guides

[SHIFT] while moving an object with arrow keys enables 1 pixel nudge

[SHIFT] while resizing preserves the aspect ratio of the object

[CTRL] while moving leaves the original object and drops a duplicate in the new location