Herbs-- used for making incense, teas, etc., that are believed to act on the brain to evoke different moods or to lend their specific energies to the ritual.
Candles-- traditional in most religious ceremonies. a good source of atmosphere lighting.
Sabbats-- the 8 Wiccan "holidays"-- known as the Wheel of the year. The meaning of the sabbats have many layers, they reflect the cycles of nature, the cycles of our lives and the cycles of Divinity. Waaaayyyy too much to go into here.
A good place to learn more in detail about them is squidoo.com/wheeloftheyear
Worship-- like any other religion. We believe in a Higher Power (God & Goddess)... therefore we worship. We give thanks. We pray. We seek guidance. We reflect on our beliefs.
Ritual Structure- can vary depending upon the group or person. Usual it involves cleansing and preparing yourself/space, casting a circle (a barrier marking the sacred space), consecrating the tools and supplies, invoking the elements/quarters, invoking Goddes and/or God, observance based on the occasion which may include readings, meditations, seasonal enactments, stories, or other spiritual activities and exercises, maybe a spell, meditation, "simple feast" (type of communion) and libation, then closing it all by thanking God/dess, quarters, breaking the circle, etc.
Pagan is an umbrella term for many different religions.
Wiccan is one specific religion that falls under the Pagan umbrella. It is a reconstruction / reinvention of Northern European Pagan religions and the practice of Witchcraft, heavily influenced by things like Freemasonry, ceremonial magic & Eastern philosophy. It is something of a "patchwork" religion.
Wicca has many different traditions, or "trads" but groups (or individuals) are autonomous. There is no higher church.
Just about anything by Gerald Gardner, Doreen Valiente, Viviane Crowley, Janet & Stewart Farrar, Raymond Buckland, Scott Cunningham or Ronald Hutton.
Might I suggest next time breaking the questions down into individual questions... all of these questions would require involved answers.
Nearly 20 years being Wiccan