Who may apply? An overseas national who has married a British citizen may apply for a marriage / spouse visa.
How long may I stay in the UK? A marriage / spousal visa will normally be issued for one year.
Does it allow me to work? Yes.
One month before the marriage visa expires you may apply for residency to remain in the UK indefinitely. You would need to be able to prove that the marriage still subsists and that you and your spouse had been living together as a married couple over the course of that year.