I worked part time on the weekends, but during the week I was completely focused on school. To tell you guys honestly if I had it to do all over again I would not of gone to school I would of worked full time for a really good chef. When I say really good chef I don't mean Charlie Trotter or someone on that level. What I mean is someone who is willing to take you under their wing and teach you the basics (stocks, sauces, cooking techniques) and how to run a kitchen. As for learning about cost control and sanitation I would simply taken just those courses which you can do at most school. Many of the classes you take at culinary school you never use at all. Just my two cents.
One other option is to forget school and do two jobs which is what I did. Work in the morning at a butcher shop for a few hours and learn how to butcher meat properly and get paid. Then at night work at a restaurant. I did this for a while and found it much more beneficial. I worked at an ice house learning ice carving in the morning (3 days a week) and then worked at night in the restaurant.
Taking school out of the equation does many good things in my opinion. One, you save a ton of money. Two, much of it you can learn on your own with the same books you would use at school and working in the real world. Third, it really helps you understand early on if you want to actually be in the restaurant business and live that life and put that life on your family.