Begin by listening to the music and becoming familiar with the samba beat. Samba is typically counted in 2/4 time (2 beats to 1 bar of music). The tempo for samba is 100 beats per minute or 50 measures per minute.
The footwork is timed 1-a-2, 2-a-2. The "a" represents the bounce. There is a "Samba Bounce" action that is specific to the dance. Begin by incorporating this bounce into the music by simply feeling it with your body. You can tap your hand, compress into your knees, or move with your upper body. Just feel the beat. Describing the basic samba step may be too complex for written word, so viewing one of the videos is recommended.
The best way to learn the samba dance correctly is through dance instruction. Find a group class in your area or take private lessons in order to learn and improve your samba technique. Samba is one of the more complicated ballroom dances and may require an outside perspective.