We use our playroom/computer room for our some of our family subjects. We have a child sized table for my younger dd's to sit and do their wok while our 8 yr old dd sits at the kitchen table. We do science and art/drawing at the kitchen table. We read literature in our living room. I figure homeschooling is an extension of our family life so we just do our work where we are most comfortable and put it away when finished. I have each girls workbooks for math, copywork, reading, and my books stored separately in magazine holders from walmart and stacked on the top book shelf in the playroom. I store away art supplies, games, puzzles, and extra toys in tubs away in our pantry closet in the utility room off the kitchen.
I'm working on reorganizing and have decided to keep 4 yr old dd's prek manipulative out where I can see them on the playroom book shelf or else I forget what I have for her that she can do. lol I'm not good with scheduling something special for her to do on a weekly basis, like counting objects or working on alphabet letters with games. I get so focused on the older two she just joins in and picks up everything basically. She counts because she does calendar with us, i.e. I'm also going to start switching toys around 2x per month and see how that goes instead of having a majority of the toys out (We have a play area in our basement as well.) They are blessed with many things from 4 sets of grandparents!