Division of Polynomials from Mathisfun – a really clear explanation:
For further notes & examples on operations with polynomials, see the following resources:
From the mathcentre which has an extensive collection of very clear notes and other resources the Algebra collection includes Polynomial Division.
Another reliable source is Tony Hobson’s Just the Maths, This includes a document with examples of Polynomial division: Just the Maths Algebra(8) – Polynomials.
Another source is David Smith’s site ‘The Maths Teacher’ which includes Algebraic Multiplication and Division under Algebra AS level.