Tikanga can be different for each marae - you should check what the kawa (protocol) is for a marae before visiting. Here are some general resources from the library:
____________________________
The marae visit by 
Pōwhiri in action: He kete o te reo Pōwhiri by _____________________________
Tikanga Māori: Living by Māori values by 
Tikanga whakaaro: Key concepts in Māori culture by 
He hīnātore ki te ao Māori: A glimpse into the Māori world by 
Te Kōparapara: an introduction to the Māori world by 
Ki te whaiao: An introdcution to Māori culture and society by 
Te taiao: Māori and the natural world by 