My daughter (nearly 4) is very comfortable with her alphabet - largely thanks using to LeapFrog Fridge Phonics
for the past year or 2.
I bought these books to go the next step, and take advantage of her interest in letters and words. Schools are all using phonics to teach reading these days, so to fit in with what they learn at school, do use a phonics system.
They are perfect. 12 very short books based on (book 1) 4 sounds, and adding 2-3 sounds for subsequent books. A few minutes work will finish the book.
Make sure your child is reading ready first. A sound knowledge of the alphabet, and an interest in words is important. Ensure that they know the phonic (sound of the word) and not just the letter name.
You will need an understanding of phonics yourself - not all of us learned to read this way - and some sense of how to blend the sounds to make a word. A "teach your child to read" book may help you with this. ( Teach Your Child To Read : A Phonic Reading Guide for Parents and Teachers
is one resource. I haven't read it personally.)
The child is learning a challenging new skill. You will need patience. Make it into a game as far as possible (My wife is better than me at this - racing to see who can get the word first - but daughter usually wins!) and keep it light hearted. It is important that it is fun.
I am finding that one read of a book is insufficient. The books are challenging on first view. Book 3 was definitely a struggle, but on revisiting book 1, my daughter read it from end to end with barely any help. The joy on her face when she finished - to appropriate cheers from mum & dad - was a sight to remember!
If your child is not ready, put the books away for a few months. Reading skills reap their full reward when it is fun.