The BEST stimulation you can provide to your child is yourself MUMMY.
Commuications is the KEY.
Patience from Mummy is important.
Providing a FUN environment to learn... is very stimulating to learn. (as I always remind younger Mummies.. to literally 'dedicate' a time and tell their kids .. this is learning/study time. It can become very regimental and can be uninteresting, especially to older kids). Mummy should be more animated. For example, like a simple book like Three Little Pigs... you can make it very animated... change of tone.. introduce action. This will promote the love to read books. Promote two-way communications by talking and asking them about the story. Mummy just have to be creative and enjoy this special moment yourself.
Learning should NOT be a dedicated time.. it should be at ALL times. Not necessary just textbook based. Seize all opportunities to bring them around.. to introduce NEW things to them. Could be supermarket.. teach them about names of fruits and vegetables. Learn about colours. Learn about arithmetic.. Again, back to Mummy, how to be creative and create this FUN opportunity for them to learn... .
Kids like a BIG SPONGE... they can absorb so much that can shock their Mummy.
My kids were able to read at 18 and 20 months. According to their Pediatrician, that's pretty early. Believe by putting all of the above 'ingredients" together works. That's my personal opinion.
I read alot on parenting and one of the books which I would like to recommend to chart their growth and development (some kids progress faster than what is presented.. like mine...it serves well as a guide).
WHAT TO EXPECT THE TODDLER YEARS - Arlene Eisenberg,Heidi Murkoff and Sandee Hathaway. Publisher : Workman Publishing, New York.
Try reading it if you can.