The lead guitar player in a band is the guy who plays the solos. They may be extended instrumental breaks in a song or just licks interspersed with the vocals. Many guitar students, after becoming competent in playing chords, feel that learning to play lead is the next step. This feeling is often inspired by watching a lead guitarist effortlessly play notes all over the guitar neck.
As well as learning the techniques involved in learning to play lead guitar, there’s the question in the beginner’s mind concerning how the lead guitarist knows which notes to play and whether he learns his solos off by heart or just improvises.
In order to play lead guitar you will know about the minor and major pentatonic scales and the so-called "blues scale". There is not a lot of basic knowledge needed, just a few notes, but you will need to learn where to find these sequences of notes in any position on the guitar fretboard and then have the time and energy to practice playing theses scales till you can play them in your sleep.
The pentatonic scale in A minor consists of the notes A C D E and G. Here is the tab for the A minor pentatonic at the fifth fret:
It might make it a little less daunting to see this task as learning the scale in three positions on the neck: the first, fifth and twelfth frets. So, they are your starting points.
Here is a diagram of the notes on the guitar to help you get started. It might be an idea to save it on your computer and print it out. Then you can mark the notes you are trying to memorize on the printout. Start by practicing the scales up and down for a day or two, then you can start to see how they sound if you mix them up.
And here is the tab for the blues scale in the key of A.
When you practice these scales, use a metronome and don’t bother trying to play fast. Just play cleanly with equal spaces between the notes. You can vary your picking strokes between alternating up and down, or all up strokes, or all down strokes.
Once you have got the feel of the blues scale you can start playing some licks. This YouTube video shows you some A minor pentatonic licks: