A simple practice session might look like this :
Theory - 10 minutes (or more if your are working on a long tutorial)
warmup - 5 minutes
Exercises - 20 minutes (chords changes, scales exercises)
Break - 5 minutes
Fun stuff - 20 minutes (learning a song that includes the chords you've learned)
Practice should be used to reinforced what you've learned in the courses. Most of the things you'll learn needs to be played over and over again to become second nature. This is where most guitar player have trouble with and a lot of them quite because they don't give themselves the time to learn.
Practice sessions are extremely important and don't need to be 2-3 hours long. Most of us can't fit long practice sessions into our schedule anyway.
A good warm-up exercise would be Lisa's Spider exercise.
As for the exercises they can be made up of any of the exercises lessons you'll find in the courses. There's ton of them and it's a good opportunity to work on those giving you the most trouble. You could also take any exercises you feel comfortable with and work on speed and accuracy.
I hope this helps you out.
