In what ways did the Wampanoag help the colonists survive?

The greatest contributor to the survival of the colonists was their relationship with the Wampanoag Indians. Squanto, an English-speaking Native American, established relationships between the colonists and the Massasoit Native American Tribe. His knowledge of the Massasoit people, and his knowledge of the English language, ensured that a peaceful climate existed and that both groups could thrive.
In addition to this, the Wampanoag worked with the colonists to plant and harvest crops such as corn, beans, and squash. Collectively called "The Three Sisters,” this food source became a staple of the colonists’ diet. The newly-arrived colonists had little working knowledge of an agrarian lifestyle and were perplexed by the rocky soil they encountered. In addition to this, many of the early settlers had left a life in the trades. The Wampanoag gave the colonists a great gift by teaching them agricultural skills.
All in all, the Wampanoag helped the colonists survive by teaching agrarian skills and by ensuring a peaceful existence remained between the indigenous people and the colonial settlers.

In short, the Wampanoag tribe of Native Americans (and especially the famous Squanto, whose actual name was Tisquantum) aided the Pilgrims by helping them learn about crops, land, and the Massachusetts climate.  This helped establish a peaceful relationship between the two groups of people.
The Wampanoag, specifically through Squanto, also became the "middleman" between the Pilgrims and the Massasoit.  This was a much better position than the Wampanoag being the enemies of the Mi'kmaq tribe (a serious problem before the Pilgrims arrived).
The Wampanoag, through Squanto, further helped the Pilgrims in translation to Native American speech.  Squanto acquired this ability when he was captured as a slave and subsequently freed.  Squanto's translation services to the Pilgrims helped initiate a peace agreement.  It also helped to initiate the "First Thanksgiving," where the two groups simply got together after the harvest and feasted.