Help 4 year old learn alphabets

I highly recommend Leapfrog Letter Factory. The songs in the DVDs are catchy and easy to learn. My kids able to memorize the letters and their sounds within a week. Also, after they learn the letters and sounds, you can reinforce with alphabet puzzles. For me, I also start to introduce beginning sounds using picture cards. You can get a lot of ideas from pinterest and free templates are available for download.