Rest days

I checked the FAQ but if I missed this question let me know!

I know rest days are good. Giving your body time to relax and recoup after day(s) of working out. I am now back to the gym after 3 months of laziness so obviously I'm going to be pretty fucking sore. I took today to walk 4 miles with my daughter in her jogging stroller since my legs were killing me from the day before (I basically looked like QWOP when walking down the stairs). My question is, how often should you give your body a day of rest? I was looking at working out 3 days, rest day, working out 3 days, rest, and so on. I have been losing weight but want to start toning and building muscle as muscle can help burn excess while I'm not working out. I just want to make sure I take care of myself and not over do it.

Edited for spelling.