I find that unless I have something in particular planned that it's very hard to just make time for the kids. Reading a book with them, is always good of course, but I find arts and crafts with them more rewarding. I recently came across a great activity book that a friend recommended to me. Pencil Play Pals Pencil Games. Got it from
pencilplaypals.com
It's great. It shows you how to make games from stuff you'd usually just throw away, like a cereal box. You need some pencils too. The games are simple enough but my son who's just 6 needs a little help. Which is great because that's how I think this book should be used. A way to spend time doing something with your kids. So you get to make a game together and play the game when you've finished. I think this is much better than just buying them a new toy that they don't really learn anything from. My son's always very pleased with himself when he's made a game. I think he's learning a lot from it.