Since I first began homeschooling I have had preschoolers in the home. You have to plan for your preschoolers just like you do your "school-aged" children, sometimes even more. Preschoolers can not be expected to entertain themselves, watch TV all day, or stay out of the way and be quiet.
Actually I love preschool! I enjoy planning for my preschoolers, and I enjoy doing preschool activities with them.
Always spend time with your preschooler first. Our day begins with chores, breakfast, and the Bible lesson. The very next thing is preschool time. The older children begin their schoolwork independently while I spend about 30 minutes with the preschooler. During this time the activities vary depending on the age of the preschooler. Until they are four, I typically use this time for playing simple games, reading books, playing with play-doh, playing with toys, or teaching them how to play with the activities that I keep in boxes in my schoolroom closet ("educational things"). At age four, I shift my preschool time to more direct instruction. I teach an alphabet letter a week--its sound and how to recognize and/or write it. We do art projects that correspond with each letter, for example, glue feathers on the letter f. I use Get Ready For the Code workbooks as well as a few other preschool workbooks. This year I bought two workbooks from Building Thinking Skills and one from Sam's. We do a couple of pages at a time. Girls seem to enjoy this more than boys, so I adjust my expectations accordingly. Leah will probably want to do the whole workbook in one sitting! So my 30 minutes of preschool time with Leah this year will look something like this:
2. count the days of school (big celebration on day 100!)
3. Get Ready For the Code pages
4. a couple of other workbook pages (alternate the books)
5. art project or other activity (games, puzzles, teaching our phone #, etc.) I have these activities listed in my notebook.
Then after our preschool time together, the preschooler plays with educational activities alone or with a sibling until lunchtime. I have a list of 40-50 items that I rotate, using 2-4 things a day. Some of these activities are contained in a box, some of them have to be set up beforehand (like a water dropper activity).
Be warned--older children love preschool! They will beg you to do the games and activities with the preschooler! My three older children take turns playing with the preschoolers 30 minutes at a time while I work with another older child. We play "pass the baby (or toddler or preschooler!)" until all of our schoolwork is done--or until lunch. After lunch when your preschoolers nap or rest you can finish working with the older children if you need to.