This is what worked for us:
THe BEST preschool resource (IMO) is "The Beginner's Bible for Toddlers" read it every day.
THIS ONE (not look-alikes : )
http://www.amazon.com/Beginners-Bible-T ... r+ToddlersHe's not too young for phonemic awareness. With DD, I got a stack of books of different brands (from the thrift store) that were on a "my first alphabet" theme. Then we'd read "A says /ah/ "Apple" or "A says /ay/ Airplane" (that's the best I can represent the phonetic sound without proper symbols) for each letter. Since each book had different pictures, she got the concept that a could start many words and could have more than one sound, and she learned the name, the sound and an example all together.
I also got Meet the PHonics video series from the library (probably worth buying!) They were a big help : )
This really helped with her speech, too. Because I could say things like, "no, not "firsty" with an f - THIRSTY with a TH." And, she would understand and fix her speech : )
I had the leapfrog alphabet thing you mentioned - it was okay but not great. It is sometimes hard to tell what sound Tad is saying, which REALLY doesn't help with phonics. WE got ours cheap from the thrift store - I don't regret it - but I didn't find it that all helpful.
I also read number books. "Baby has 9 trucks" "Let's count the trucks" (this involves counting each number from 1-10 a million times for him. He probably won't count along with you for a long time. Your big kids could do this one for you ; )
Youtube vidoes for playlist from Sesame street & other sources that teach sound concepts - like the TH sound or SH sound, etc.
Coloring & cutting are great for motor skills - as is play-dough and even helping you cook!
When you get to the point that you can say "What sound does "fan" start with" "what sound does "bus" end with?" and he can answer this sort of question well - he is ready to start phonics.
Flannelgraph Bible Stories are great for both teaching Bible and for word-reality connection.
DD LOVED using a microscope for science when she was 3 - it was VERY exciting (once again, a cheapo from the thrift store)
Songs to teach memory things. We did stuff like Like Jesus Loves Me, 12 Disciples songs, planets songs, books of the Bible songs, etc - these teach music, enunciation, memory, and literary skills : )
Anyway - that's probably enuf for now : )