Watch the Fretting & Finger Strength online guitar lesson by Stu Hamm from Learn Bass 1: First Steps for Beginners
Now that we've talked about open notes, it's time to talk about fretted notes. So, if you played an open A, and then played the fifth fret on your E string, that's the same note as your open A. This is the same for every string: 5th fret on the A string is the same as the open D below it, and 5th fret on the D string is the same as the open G. As I said before, you want your hand nice and arched like you're holding a tennis ball in order to hit the notes with your fingertips. You also want to be playing these as close to the fret as possible.
So for this rhythm, we'll be playing a fretted A, D, and G. We'll be playing two half notes and four quarter for each note. We'll start with the fretted A (5th fret) on the E string, then move to the D (5th fret) on the A string, and then play the G (5th fret) on the G string. The first time through we use our index finger, but the second time through use your middle finger, and then the next time use the ring finger. Finally, we'll go through it using our pinky. It's important to press down your other fingers below the fretted note in order to strengthen your pinky finger.