How do you tie two pieces of rope together?

So I’ve been working through the instruction videos from ‘Two Knotty Boys’, but often they use ropes that are much longer than what I have. This brings me to ask: what is a good (easy, efficient and elegant) method for joining two pieces of rope? It occurred to me that a metal ring could work well here too, but then the question becomes: how should it be tied best? So really two questions:

• how to join 2 ropes together (using their loose ends)
• how to attach a rope to a metal ring

wikipedia is your friend: just splice them together. hope that helps