The first section of Inferno is known as the Dark Wood of Error. In it, Dante introduces several key characters and some of the major concepts of Inferno.

The opening image is that Dante has, at age 35 ("Midway in our life's journey") gone to a path of sin. He realizes this and tried to correct his course, but is forced back into the Wood of Error by Three Beasts, a lion, a leopard, and a wolf. Allegorically, each of these represents a type or class of sin. While trapped in the wood, Dante meets the shade of Virgil, the Roman poet, who explains that he has been sent as a guide to Dante to help him progress from a state of sin to a state of salvation.

Characters:
Dante Aligheri: Dante is both author and character in Inferno. As such, he represents both a real person and the allegorical concept of the human soul. The essential point of Inferno is that a trangressing soul must travel through three stages to salvation: recognition of sin (Inferno), cleansing of sin (Purgatorio), and redemption from sin (Paradiso).
Virgil: Virgil, like so many others in Inferno is a real person turned into an allegorical character by Dante. The real person, Publius Virgil Maro, was a poet in the time of Ceasar Augustuswho was exiled from Rome. His great epic, the Aeneid, is generally viewed as an attempt to get back in the graces of the Roman ruler and so have his exile lifted. Dante would have felt affinity for Virgil for several reasons including the shared sentence of exile and a common Italian heritage.
Beatrice: The great passion (not to be confused with his wife) of Dante's wife was a woman names Beatrice Portinari. To Dante, who saw her when he was young and seemeingly never had any real contact with her, Beatrice became the symbol of ideal, courtly love. It is she who represents Divine Love in Inferno, and she serves as the intercessor on Dante's behalf and his guide through heaven in Paradiso.
Rachel
Mary

Beasts:
external image darkwood4.jpg
The She-wolf -- usually associated with the sins of incontinence or the sins of upper hell. Quite possibly, she is supposed to be associated with Romulus and Remus, the twin founders of Rome who were said to have been nursed by a she-wolf.
The Lion
The Leopard

Images and Constructs:
The Dark Wood:
The City on the Hill