General roles of goddesses in Hinduism.

Can someone please explain the general roles of goddesses in Hinduism.
Also, out of one of the goddesses that you describe can you explain her particular role within Hinduism.
If I can get just part of the question answered that would be great, thanks to all.

Okay can someone just at least answer this one question then? What is the general roles of goddesses in Hinduism? I was able to answer the second part of the question and just need this question answered. Please!

In Hinduism, the Supreme Reality (Brahman) manifests itself in both male and female form. Every major god has a goddess counterpart (or consort), and many Hindus worship the Great Goddess exclusively. Although in the Chinese yin-yang duality, the feminine side is dark and passive, in Hinduism the feminine is highly active. In fact, the word for "goddess" in Hinduism is shakti, which also means "power" or "energy." Followers of Shakti or Devi, the Great Goddess, are called Shaktas. Just as the masculine aspect of Brahman is manifested in several different gods, so does the feminine aspect of the divine take more than one forms. This article outlines the major Hindu goddesses, all of which are manifestations of Shakti.
Sarasvati: The Hindu Muse
Sarasvati (also spelled Saraswati) is perhaps the most ancient goddess that is still widely worshipped today. She is the Hindu muse: the inspiration for all music, poetry, drama and science. Musicians pray to her before performing and students ask for her help before taking a test. She is the wife or consort of Brahma, the creator god who is rarely worshipped anymore.
In statues and paintings, Sarasvati is fair-skinned and dressed in white to symbolize pure illumination. She rides a swan or a goose, and has four hands: in one she holds a book; in another she holds prayer beads (because she is the source of spiritual knowledge, too); her other two hands hold a vina, a sitar-like musical instrument. Not suprisingly, Sarasvati is especially revered by students and teachers. At the beginning of spring (January-February), her image is taken out in a jubilant procession. She is also a popular goddess in Jain and Buddhist mythology. This is the absolute best and most detailed explanation I could possible write. :-) I hope it answers your question fully.