Hold a barbell at your shoulders, dip slightly at the knees, then drive up and press the bar overhead. Lock out at the top, then lower back to shoulders with control.

Weight recommendations:
Beginner: Try just the bar first or dumbbells
Intermediate: 10-20lb plates on each side of the barbell 

Advanced: 25-35+lb plates on each side of the barbell

*Modification: use dumbbells instead