Watch the Inhale online guitar lesson by Jeff McErlain from Beginner Blues-Rock Soloing
I cannot say enough good things about David Gilmour as a guitar player. It's almost impossible to be a rock fan and not have heard his guitar playing extensively. He's an excellent player to check out as a beginning soloist. I'm certainly not saying he's easy to play, but his solos are very melodic and therefore a great place to start.
In my mind, he has two different kinds of solos - "Comfortably Numb" is a perfect example of this. We have the first solo in the song, which is very melodic and an integral part of the song as a composition, and the second solo, which sounds a little more improvised and bluesy. When learning some of his playing, I would lean towards the first kind of solo.