In your evolution as a lead guitarist, it becomes more and more important to learn to solo in more than one position. If, for example, you're soloing in the key of C major, and you only feel comfortable playing in the few frets surrounding the eighth fret, then you're limiting yourself unnecessarily. What follows are diagrams and explanations of how to play a major scale in every position on the neck of the guitar.
The first position of the major scale, seen above, is the "standard" way of playing the major scale, which most guitarists know. If it looks unfamiliar to you, play through it. This is the "do re mi fa sol la ti do" scale you probably learned in school. Begin the scale with your second finger, and do not adjust your hand position while playing the scale. Make sure to play the scale backwards and forwards, slowly and evenly, until you have it memorized.