SN45.x Magga-samyutta -- On the Noble Eightfold Path

• [SN45.1] Avijja Sutta-- Ignorance.

The Buddha explains that ignorance is the cause of wrong view, wrong resolve, wrong speech, etc., whereas clear knowing gives rise to right view and all the factors of the eightfold path.
• [SN45.2] Upaddha Sutta-Half (of the Holy Life).

In this famous sutta the Buddha corrects Ananda, pointing out that having "admirable people" as friends is not half but the whole of the holy life. (For more about this special kind of friendship, see the page on kalyanamittata.)
• [SN45.8] Magga-vibhanga Sutta - An Analysis of the Path

A summary of the Noble Eightfold Path.
• [SN45.171] Ogha Sutta - Floods.

Many discourses speak of "crossing over the flood." This discourse lists the floods that should be crossed over, and how it should be done. [TB]

SN46.x Bhojhanga - The Seven Factors of Awakening.

• [SN46.1] Himavanta Sutta - The Himalayas (on the Factors of Awakening).
  A summary of the 7 Factors of Awakening.
• [SN46.14] Gilana Sutta - Ill.
  The Buddha instructs Ven. Maha Kassapa, who is very ill, on the 7 Factors of Awakening.
• [SN46.51] Ahara Sutta - Food (for the Factors of Awakening).

The Buddha describes how we can either "feed" or "starve" the wholesome and unwholesome tendencies in the mind according to how we apply our attention.

SN47.x Satipatthana - the Four Frames of Reference (Foundations of Mindfulness).

• [SN47.6] Sukunagghi Sutta - The Hawk.
  The Buddha uses a lovely parable -- that of a hawk catching a quail far outside the quail's familiar hunting ground -- to reveal the need for keeping the mind in its proper territory: the four frames of reference.
• [SN47.7] Makkata Sutta - The Monkey.
  The Buddha recommends keeping the mind in its proper territory -- the four frames of reference -- to prevent it from becoming ensnared, like a monkey in a tar trap.
• [SN47.8] Suda Sutta - The Cook.
  The Buddha explains how progress in meditation depends upon noticing clearly what leads the mind to concentration and what does not, and on adjusting one's practice accordingly, just as a good cook adjusts the spices of his dishes.
• [SN47.13] Cunda Sutta - About Cunda (Sariputta's Passing Away). 
  A touching account of Ven. Ananda's grief over Ven. Sariputta's death, and of how the Buddha consoled him with Dhamma: make the Dhamma your island, your true refuge!
• [SN47.19] Sedaka Sutta - At Sedaka (I: The Acrobat).
  Is meditation a selfish endeavor? Using a lovely simile of two acrobats, the Buddha resolves this question decisively.
• [SN47.20] Sedaka Sutta - At Sedaka (II: The Beauty Queen).
  How solid is your concentration? Try this test, proposed by the Buddha: Can you keep a glass of oil balanced on your head while your favorite movie star is singing and dancing right in front of you?
• [SN47.40] Satipatthana-vibhanga Sutta - Analysis of the Frames of Reference.
  A summary of the four Frames of Reference, and how they are to be developed.

Sn48.x Indriya - The Five Faculties

• [SN48.10] Indriya-vibhanga Sutta - Analysis of the Mental Faculties.
  A summary of the five mental faculties: conviction, persistence, mindfulness, concentration, and discernment.
• [SN48.41] Jara Sutta - Old Age. 
  The Buddha, now a wrinkled old man -- but one who has conquered aging, illness, and death -- issues a powerful rebuke against old age.
• [SN48.44] Pubbakotthaka Sutta - Eastern Gatehouse.
  The Buddha and Ven. Sariputta discuss conviction, and whether it is present in those who have seen the Deathless. They concur that until one experiences the Deathless for oneself, one can only take its existence on faith.

SN49.x Sammappadhana - The Four Right Exertions

SN50.x Bala - The Five Strengths

• [SN50.15] Brahmana Sutta - To Unnabha the Brahman.
  Ven. Ananda explains to Unnabha that the path of Dhamma is one with a definite goal -- the abandoning of desire -- which can only be attained by developing a strong desire to end desire.
• [SN50.20] Iddhipada-vibhanga Sutta - Analysis of the Bases of Power.
  The Buddha explains how the four Bases of Power are to be developed.

SN51.x Iddhipada - The Four Bases of Power

SN52.x Anuruddha - Ven. Anuruddha.

• [SN52.10] Gilayana Sutta - Illness.
  Ven. Anuruddha explains to the other monks how he keeps the pain of his physical illness from invading the mind.

SN53.x Jhana - Jhana (mental absorption).

SN54.x Anapana -- On mindfulness of breathing

• [SN54.13] Ananda Sutta - Mindfulness of Breathing (to Ananda)
  The Buddha explains to Ananda how the sustained practice of mindfulness of breathing (anapanasati) leads, by stages, to full Awakening.

SN55.x Sotapatti - Stream-entry.

SN56.x Sacca -- On the Four Noble Truths

• [SN56.11] Dhammacakkappavattana Sutta - Setting the wheel of Dhamma in Motion

This is the Buddha's first discourse, delivered shortly after his Awakening to the group of five monks with whom he had practiced the austerities in the forest for many years. The sutta contains the essential teachings of the Four Noble Truths and the Noble Eightfold Path. Upon hearing this discourse, the monk Kondañña attained the first stage of Awakening, thus giving birth to the ariya sangha (Noble Sangha).

• [SN56.31] Simsapa Sutta - The Simsapa Leaves.

The Buddha compares the knowledge he gained in his Awakening to all the leaves in the forest, and his teachings to a mere handful of leaves. He then explains why he didn't reveal the remainder.

• [SN56.48] Chiggala Sutta - The Hole.

Here is the Buddha's famous simile of the blind sea-turtle, illustrating the precious rarity of this human birth.