The Wiccan Rede
As with many things in Wicca, there are multiple versions of the Wiccan Rede. When Wiccans refer to the Rede, you can be sure that they are refering to the eight words of the short version, "An it harm none, do what Thou will."
The expanded version, which is often used on Wiccan samplers and plaques because it is relatively short but is more elegant than the eight words alone, is rendered very artistically below by Python.

Below is the longer version of the Wiccan Rede, which can be found in many different versions with minor alterations. The version below was reconciled from two different versions that I had. One was in couplets and the other in quatrains. I've kept them in quatrains just to conserve space. The reader will have to decide which they wish to use.
I've reordered the wind calls to be in the order called in circle since the two versions I had disagreed on the order of some of the verses. I've also taken poetic license and changed a few lines from the version that I had because the scansion has always bothered me on the line that says "Live and Let live". I've changed that to "Live Thee freely and Let live" because it scans better. The same with "speak little, listen much", which I've changed to "speak thee little, listen much." If you don't like it, please feel free to return it to it's original form.- BlackFire :-)
Bide the Wiccan Law Ye must
In Perfect Love and Perfect Trust.
Live Thee freely and Let live,
Fairly take and fairly give.
Cast the Circle thrice about
To keep all evil spirits out.
To bind the spell every time
Let the spell be spake in rhyme.
Soft of eye and light of touch,
Speak Thee little, listen much.
Deosil go by the waxing moon,
Chanting out the baneful rune.
Widdershins go when the moon doth wane
The werewolf howls by the dread wolvesbane.
When the Lady's moon is new,
Kiss the hand of Her, times two.
When the moon rides at Her peak,
Then your heart's desire seek.
Heed the North wind's might gale,
Lock the door and drop the sail.
When the wind blows from the East,
Expect the new and set the feast.
When the wind comes from the South,
Love will kiss Thee on the mouth.
When the wind blows from the West,
Departed souls will have no rest.
Nine woods in the cauldron go,
Burn them fast and burn them slow.
Elder be the Lady's tree,
Burn it not or cursed you'll be.
When the Wheel begins to turn,
Let the Beltane fires burn.
When the Wheel has turned to Yule,
Light the log and the Horned One rules.
Heed Ye Flower, Bush and Tree,
By the Lady, blessed be.
Where the rippling waters go,
Cast a stone and truth you'll know.
When you have a true need,
Harken not to others greed.
With a fool no season spend,
Lest ye be counted as his friend.
Merry meet and merry part,
Bright the cheeks and warm the heart.
Mind the Threefold Law Ye should.
Three times bad and three times good.
When misfortune is enow.
Where the blue star on thy brow.
True in love ever be,
Lest thy lover's false to thee.
Eight words the Wiccan Rede fulfill:
An it harm non, do what ye will.
And finally, the lesser known Witches' Creed, of which I had only one version.
Hear now the word of the Witches, the secrets we hid in the night,
When dark was our destiny's pathway, That now we bring forth in the light.
Mysterious Water and Fire, The Earth and the wide-ranging Air,
By hidden Quintessence we know Them, and we will keep silent and dare.
The birth and rebirth of all Nature,the passing of Winter and Spring,
We share with the life Universal, rejoice in the Magical Ring.
Four times in the year the Great Sabbat returns and the Witches are seen,
At Lammas and Candlemas dancing, on May Eve and old Halloween.
When daytime and night time are equal, when sun is at greatest and least,
The four lesser Sabbats are summoned, again Witches gather in feast.
Thirteen silver moons in a year are, thirteen is the Coven's array,
Thirteen times at Esbat make merry, for each golden year and a day.
The power has passed down the age. Each time between woman and man.
Each century unto the other, ere times and the ages began.
When drawn is the Magickal circle, by sword or athame of power,
It's compas between two worlds lies, n the land of shades of that hour.
Our world has no right to know it, and the world beyond will tell naught,
The oldest of Gods are invoked there, the great work of Magic is wrought.
For two are the mystical pillars, that stand at the gate of the shrine,
And two are the powers of Nature, the forms and the forces Divine.
And do what thou wilt be the challenge, so be it in love that harms none,
For this is the only commandment, By Magick of old be it done.
Eight words the Witches Creed fulfill:
If it Harms none, Do what Thou Will!