Oh the busy times I have had!
Time management is not easy, but it's fairly do-able. Most people use something like a planner, if they prefer paper, or using their smart phones these days for keeping schedules all together. Having school and work at the same time is a really difficult thing to do, and when I was doing it, I found it really helpful to plug all my shifts and classes into my iPhone (which has become my brain, practically) so I don't forget them.
Otherwise, I would say that you should keep workout times around the same time every day. Our bodies like schedules and you'll find yourself actually craving the workout, food, work or anything else if it happens at the same time each day! Also try to keep your workout about 2 hours away from going to bed at night- you don't want to be high and raring to go off your workout and needing to go to sleep! You could even use that high feeling to your advantage, either putting it right before work, or homework!
Be sure to give yourself free time, hopefully every day. Don't schedule your whole day right down to the hour, because sometimes other things come up! What if you want to do some gaming, hang out with friends, or something else? Or what if you're blindsided by a project? (Hopefully not, if you keep things organized! I'm just learning this now!) At least an hour, hopefully two or three, each day would be really good.
Be sure to have rest days! Very important!
And really... it's sort of a personal process! Lots of people make their planners into a kind of creative project, where other people like it just for function. Some people love to check and double check their planners (like me!) and others only need to write it down to remember. Lots of people have different styles and ways of remembering what's going on!
And, if you're really bad with time, the way I am... you can also time how long it takes you to get home from work or school, or takes you to get between work and school, how long you like your workouts, and things like that. Then you get an accurate idea of how long things take, rather than thinking "Oh dear, I have an 8 hour shift today... I can't do ANYTHING else!" Which, frankly, is completely not true! And dancing on stressful days, or days where you feel awful after work, totally helps. I'm serious. Even if you feel awful and just want a nap!
And now I have to go and practice what I preach... >_>