What makes a good stay at home mome?

Hello Ladies,
My son is nearly 4 and aside from the 8 weeks post-delivery, I have been a working mom, 4 days a week. This works well becuase I can work and earn a good paycheck and still have time to spend with him and a weekend becuase I do all the cleaning and errands on my day off. I am looking at working from home now and wonder what it takes to be a stay at home mome? My fridays are busy and sometimes my son does get ignored, I guess not really ignored, but does not get my attention. So I end up going back and forth on cleaning and letting him help or watch a movie and then taking time to sit with him and spend time together. So, how do YOU do it? I do not want to be the wife, like several of my friends, who are stay at home mome and then want their hubby to come home and cook dinner or do the laundry or clean the bathroom. I need the time to take care of the house and my job, but also be there for my son and help him be ready emotionally and academically for kindergarten.
Thanks for your help! I have always questioned if I would be good at staying home and now and kind of panicking about it!
Just to clarify, I CURRENTLY work 4 days a week and do handle 90% of the housework/errands. I am about to stay at home 24/7 and that is where my question lies.

So, if I am hearing you right, you have ONE more day off than your husband and you think that you should be able to do all the things a TRUE stay at home mom does? I think you are putting a lot on yourself. I only work three days a week and it is hard to do everything and at times hubby has to chip in some time with me.....

If you ever have watched Nanny 911, she does a chart of the times during the day with what needs to be done. That way you can schedule time with your son and still have time for your other things to get done. It also gets you and your son on a schedule and he'll get to know when it's HIS time with mommy.