The Noble Eight Fold Path is probably best understood in relation to the Four Noble Truths.
The First Noble Truth is the truth of suffering, or dis-ease, irritation, dissatisfaction (dukkha): clinging (upadana) to the five aggregates is suffering. These five are: 1) Form and Matter, the physical world around you and your physical body 2) Sensation, pleasant, displeasing, or neutral 3) Perception or Cognition, registers whether an object is recognized or not, like the sound of a bell or the shape of a tree 4) Volition, our mental habits, thoughts, ideas, compulsions, and decisions triggered by some object and 5) Cognizance, the base that supports all existence.
The Second is the Origin of Suffering: craving for sensual pleasure, existence, or non-existence occurs (tahna) because of our clinging (upadana) to the five aggregates causes renewed existence (Bhava). Bhava is the desire for more sensation, for more life.
The Third is the Cessation of Suffering: is cultivating the indwelling Buddha Nature in all beings. Cessation of craving, and not clinging to self, or non-self.
The Fourth is The Noble Truth of the Way: the way to the cessation of suffering is the Noble Eightfold Path.
Clinging (upadana) to the five aggregates is suffering (dukkha). Craving (tahna) because of clinging (upadana) causes renewed existence (Bhava). Bhava is accompanied by craving (tahna).
And yes, this is all circular. Samsara is the term for this cycle of suffering - the cycle of birth/rebirth, Bhava, which allows for craving, which allows for clinging which allows for suffering. Following the Eightfold Path is the way out of Samsara.
I included the sanskrit terms used in Buddhist literature as best I could so that if some clarification is needed, you can look up the actual Buddhist terminology.
Now for the Eightfold Path:
The Eight are divided into three categories:
Wisdom: mental and cognitive aspects of the practice
1) Right View - understanding, especially of the Four Noble Truths. Right view is necessary for the rest of the Path. As expected, wrong view, or ignorance, will lead to wrong intention, ect.
2) Right Intention - proper exertion of our own will to change. From canon 'And what is right thought? Being resolved on renunciation, on freedom from ill will, on harmlessness: This is called right thought.'
Ethical Conduct: From canon 'It is in the nature of things that freedom from remorse arises in a person endowed with virtue, consummate in virtue.' But, of course, we should not cling to virtue.
3) Right Speech - making the best use of our words. Being honest, not being abusive in speech, and refraining from mindless, idle chatter.
4) Right Action - Not destroying sentient beings, not stealing, abstaining from sexual misconduct.
5) Right livelihood - practitioners ought not to engage in occupations which, directly or indirectly, hurt other sentient beings
Mental Discipline: the best way to go about shaping the practitioners outlook on the world for the practitioner
6) Right effort - right endeavor, engaging in effort that is wholesome in terms of karma, karma being the ultimate consequences of the effort to the agent
7) Right mindfulness - paying attention to all phenomena that affect the body and mind. Being attentive to the present moment, open, quiet and alert.
8) Right concentration - right concentration is dependent on all other parts of the path. Right concentration is a singleness of mind when equipped with all the other factors.
I hope I haven't made any of that too confusing.