I'm 23, still attending George Mason University and working towards my undergrad.
Personally, I wouldn't worry about a schedule other than the one you set for yourself. So long as you stay focused and continue to chip away at it, I think you'll be alright.
As for other approaches to learning, I started working full-time in IT after high school and have been working on my degree part time ever since. (I've been continually enrolled) I think this helps in a number of ways. I've been continually pleased in how much
my job has helped my school work and vice versa, and I've noticed my career has progressed much farther already than my other friends who have graduated ahead of me. (That being said, a degree will go a long way to advancing your career.)
It's really whatever works for you best. But being thrown into the enviroment teaches you in a way school won't. If you can leverage the two then you'll really learn a ton.