A majorThe A major chord (often referred to as an "A chord", and sometimes written as "Amaj") can give new guitarists trouble, as all three fingers need to fit on the second fret, on adjacent strings. As you practice, be sure the open first string is ringing clearly... this is the most common problem when learning the A major chord. Making sure your third (ring) finger is properly curled will solve this problem.
The small gray numbers on the diagram below illustrate which fingers on your fretting hand should be used to play each note. If you're unsure of what these numbers mean, refer to the diagram on this page.