Baking in oven after machine kneading
Well-kneaded dough should be smooth and supple.  Once you have experience, you can usually tell by the feel of the dough.

Sometimes the "skin" of the dough breaks over the surface; this also indicates that you're done kneading.

The classic test is to poke the dough with your finger: if it springs back, it's been kneaded enough.

(Incidentally, the way you know the dough is finished rising is that it doesn't spring back when you poke it).