Flash cards and drilling is not considered developmentally appropriate.
I think you'll have more success with games, songs, reading stories, playing with letters, pointing out words you see "hey, I see a stop sign! S T O P...that's STOP! Make math and literature a part of your day. Let them help you make something, and allow them to measure. Count aloud as they do. Count grapes or animal crackers at snack. Help them learn to serve themselves lunch, clean up their spot, wipe the table, care for a pet or plants, build things with cardboard boxes and blankets. Most of all, give them plenty of time to play!
Here's a blog with lots of ideas:
http://www.letthechildrenplay.net/
I guess I wonder why anyone needs to be "ready" for preschool. PRE school is supposed to get them ready for Kindergarten, but what do you need to know before preschool?
