In this lesson, I learned a little more about guides, but most importantly, how to set up and customize a grip and how to work with the snap features.
By default, when you grab an object by clicking and dragging, you can have it snap to the guide as long as the cursor is intersecting with the guide. This option is called Snap to Point which can be found under the View menu. When deselected, the object to snap to guide independently.
Not only do rulers and guides help position your content, but grids as well. Head to View and click Show Grid, making a grid pattern over the document. You can customize it by going to Preferences in the control panel, then Guides & Grid, opening a dialog box. In here, you can change the color and style of the guides and grid, not to mention the grid size and subdivision.
Under the View menu, there is an option called Snap to Grid. What this will do is snap to the intersecting gridlines. You can also make it invisible by going to View, then Hide Grid.
Aleksander’s Blog 