What are the puranas that describe the life of Brahma (the four-headed God)? I want to learn more about him.
In the creation chapter of every Purana Brahma occurs.
PARÁŚARA.--I will explain to you, Maitreya, listen attentively, how this deity, the lord of all, created the gods and other beings. Whilst he (Brahmá) formerly, in the beginning of the Kalpas, was. meditating on creation, there appeared a creation beginning with ignorance, and consisting of darkness. From that great being appeared fivefold Ignorance, consisting of obscurity, illusion, extreme illusion, gloom, utter darkness. The creation of the creator thus plunged in abstraction was the fivefold (immovable) the world, without intellect or reflection, void of perception or sensation, incapable of feeling, and destitute of motion . Since immovable things were first created, this is called the first creation. Brahmá, beholding that it was defective, designed another; and whilst he thus meditated, the animal creation was manifested, to the products of which the term Tiryaksrotas is applied, from their nutriment following a winding course. These were called beasts, & and their character was the quality of darkness, they being destitute of knowledge, uncontrolled in their conduct, and mistaking error for wisdom; being formed of egotism and self-esteem, laboring under the twenty-eight kinds of imperfection, manifesting inward sensations, and associating with each other (according to their kinds).
Although in almost every Purana he is mentioned as born of Vishnu or Vishnu's form.
Vishnu form:— http://www.sacred-texts.com/hin/vp/vp038.htm
While almost some oldest Puranas like Vayu Purana, Matsya Purana kurma Purana to supports it Brahma is born from brahmana and Vishnu and Shiva as well
Creation In the beginning, there was nothing in the universe. There were only darkness and the divine essence (Brahman). It is impossible to describe the Brahman, it has no traits that can be described. When the time came for creation to start, the brahman removed the darkness and divided itself into three. These three parts came to be known as Brahma, Vishnu, and Shiva. The first object that was created was water and Vishnu slept on this water. Since Nara means water and Ayana mean resting-place, Vishnu is accordingly also known as Narayana. In this water next appeared a golden (Hiranya) egg (Anda). The egg shone with the radiance of a thousand suns. Inside the egg, Brahma created himself. Since he effectively created (Bhuva) himself (Svayam), Brahma is also known as Svayambhuva. The egg, you will remember, was golden. Garbha means womb, and since Brahma was born inside a golden egg, he is also known as Hiranyagarbha.
—Matsya Purana: chapter3