This book (real-time rendering) helped me alot! See on page 66 and 70. It has very good graphics and explenation. Quaternions are on page 72 aswell! :)
Rotation about an Arbitrary Axis
This renders the camera with the rotation done by mouse input:
void Camera::getVectors(D3DXVECTOR3& up, D3DXVECTOR3& lookAt)
float yaw, pitch, roll;
// Setup the vector that points upwards.
up.x = 0.0f;
up.y = 1.0f;
up.z = 0.0f;
// Setup where the camera is looking by default.
lookAt.x = 0.0f;
lookAt.y = 0.0f;
lookAt.z = 1.0f;
// Set the yaw (Y axis), pitch (X axis), and roll (Z axis) rotations in radians.
pitch = m_rotation.x * 0.0174532925f;
yaw = m_rotation.y * 0.0174532925f;
roll = m_rotation.z * 0.0174532925f;
// Create the rotation matrix from the yaw, pitch, and roll values.
D3DXMatrixRotationYawPitchRoll(&rotationMatrix, yaw, pitch, roll);
// Transform the lookAt and up vector by the rotation matrix so the view is correctly rotated at the origin.
D3DXVec3TransformCoord(&lookAt, &lookAt, &rotationMatrix);
D3DXVec3TransformCoord(&up, &up, &rotationMatrix);
// The Render function uses the position and rotation of the camera to build and update the view matrix
D3DXVECTOR3 up, position, lookAt;
// Setup the position of the camera in the world.
position = (D3DXVECTOR3)m_position;
// Translate the rotated camera position to the location of the viewer.
lookAt = position + lookAt;
// Finally create the view matrix from the three updated vectors.
D3DXMatrixLookAtLH(&m_viewMatrix, &position, &lookAt, &up);
With the mouse input you modify yaw(head), pitch and roll.