How many days a week should I work out for it to be effective?

I'm21 and away at school, but upon my return home at the end of the month (Yay, graduation!) I will be thrown back into a very busy lifestyle. I will be returning to my serving job for 40 hours a week, and I also have own and run my own dog grooming business that I will do in the evenings and on weekends and I create home made pet supplies (20-40 hours a week depending.) I'm also married with a house and 4 dogs so I have domestic responsibilities etc.

For the last few months I've been training with a circus performer doing aerial dance/acrobatics and I want to continue on my own once I am home. I'm trying to figure out a way to fit work outs in and how many without feeling too much pressure to do it and giving up because I'm tired. I'm trying to lose weight/tone up/keep progress I've made in training...I would be doing mostly home work outs with weight resistance, running, insanity etc (except for one pole dance/acro dance class a week) Would doing this 3-4 times a week still allow positive change for weightloss and my goals? (Nutrition of course is important as well but thats taken care of.) Does anyone have tips for work outs for busy people?