Watch the I'm Just Swingin' online guitar lesson by Corey Congilio from Rhythm Factory: Texas Blues
This first shuffle is a very typical blues rhythm. Pay more attention to the actual rhythmic notation than the chords and riff in this case. Now of course I want you to learn the riff and chords but what's really important is in measure one. Notice how the first two hits are on 1 and the and of 2. You could play this rhythm without the riff and it would still be a worthwhile shuffle rhythm to play. I give you the full barre chord shape first then, one of my favorite 7th chord shapes in measure 3. You can use this example immediately so that's why I started with it.