I want to get an amplified sound from a sound generator IC (AY-3-8910)
I plan to plug the output to a small 8ohm speaker (like the one on small toy keyboards)
How much power do I need? It's 1 Watt ok?
The speakers on those small toy keyboards are usually rated for about a half watt or less, so a one watt amplifier that is not driven to full output would be fine.
The LM386N is a good choice here. I messed about with them a bit, some years ago... easy to use, difficult to fry (as long as you don't deliberately abuse them). Google image search threw up about a million schematics to try, none of them are hard to build.