Watch the Greeny online guitar lesson by Jeff McErlain from Essentials: Chord Tone Soloing
There are many guitar players I would recommend when getting into this "sweeter" blues sound, but the man to start with is BB King. I actually came to BB a little later in my guitar playing career, which seems kind of crazy. Coming from a British blues background with bands like Cream and Led Zeppelin, my main exposure to BB was on TV shows where it was more about his singing, which I always appreciated, but I never thought much of his playing.
To put it simply, I was an idiot. Okay, well maybe not an idiot, I just hadn't heard the right stuff. So, I highly recommend BB King's Live at The Regal, Live at Cooke County Jail, and of course, maybe a greatest hits album. But those two live records changed everything for me. I also highly suggest checking out John Mayall & the Bluesbreakers' album Blues Breakers with Eric Clapton, one of the most influential guitar records of all time. Even if you don't know it, it has influenced your playing in some way.
Another guitar player who I gush about all time is Peter Green. A student introduced me to his playing about 15 years ago, and I was shocked that I had no real knowledge of him other than knowing his name. I have to say, he's probably my single most favorite blues guitar player and I cannot recommend his Fleetwood Mac era music enough. There's an excellent official release of a bootleg from when he was in John Mayall's Bluesbreakers (in which he replaced Clapton). The sound quality is a bit sketchy, but the playing is absolutely astounding. And it was 1967.