I also work full time, have two step-children (full time) and go to school in the evenings....here are some of my tips...
If you have time in the am before work - brown hamburger or bread your pork chops, or do whatever you can for dinner in the am - if you can - have hubby finish it up for you.
Buy plenty of paper plates, plastic cups are a GREAT thing with kids in the house (mine go through at least 6 cups a day!), plastic forks, etc.
A lot of my chores (aka..second job) got done in the am - I would put a load of laundry in, start browning burger while I dust the house, burger would be done, so I would get ready for work - done with that, the laundry would be done, put that in the dryer, and start a load of dishes in the dishwasher...you get the idea.
Weekends are a great time to make up to your family for the quicky dinners during the week, if you start to feel guilty like i did!!

And most importantly - take some time for yourself - it's easy to get caught up in your job, kids, and schoolwork and forget about yourself - even if it's just sneaking off to a park to sit for a half hour and read a magazine or just relax. Good luck to you!