Ruler guides you drag out from the rulers (View > Show Rulers)
If you drag them out of the page area you get page guides, if your drag them out outside the page area you get spread and art board wide guides.
You can access them also via Layout > … various menu items.
Margin guides you get from new document or from Layout > Margin and Columns…, best done on the master.
But in many cases it helpful to work with styles: Paragraph and Object Styles will help you to accomplish a lot of things automatically, like vertical centred text, etc.
Turning on Smart Guides will give you an indicator when things are centered to the page, the margins, or other objects. Ruler guides (and other objects) can be centered to either the page or the margins by selecting them and using the Align panel with the Align To: field set to either Page or Margins.