Wondering about birds.

Last week, it was almost spring like here. I heard some birds and felt the sun. This morning it is freezing and windy and I heard no birds. Maybe they are there but are being quiet. Then I realized, I have no idea how birds move. I know they fly. I can hear the whirring of wings sometimes. But, do they flap both wings together? Separately? Slowly? Quickly? Do they hold them straight out to the side or tilted? And when they land and walk, do they hop with both feet or move one at a time? Never really thought about this before. If anyone can enlighten me, I'd be most grateful.