We always loved to read!!! It would have been harder for our family to limit it to only 15 minutes per day or 400 per month.
My son loved all of the Eric Carle books at that age. We often went to the library. We found out that it is best to go to the low income part of town. There was a much better collection. Our local library was very picked over and filled with agenda type books. Let your on choose what he wants.
As for a home library, books are great gifts. If you choose something that you will read aloud to your son, make sure that it is something that you find interesting or beautiful. That way you will actually enjoy reading it for the 200th time.
We loved our book "the 20th Century Children's Book Treasury". Amazon has it for $20.00. It has 44 illustrated classic picture books for the price of two of them. We could always find a great story in this book to read. It also exposed us to stories that we might have missed - like ones about girls. I liked that he got a different perspective occasionally.
Another collection is the Harper Collins Treasury Picture Book. It is for ages 2 and up with stories like Goodnight Moon and Harold and the Purple Crayon. It has simpler stories which might be nice to have if there are also younger children in the house and for when he starts to read to you.
Teacher's First website has a list of the best books. I agree with their compilation.
Do remember that each child is individual. Let them guide you. We read for hours every day, so my eldest was very advanced. If you give a child a book that is out of his or her "zone" they will not enjoy it. It will either be boring or not within their understanding. My son's favorite kindergarten book was Charlotte's Web. He could read it independently, but that was only because we had invested about 400 minutes per week from the day he was born. Remember, you are not spending your time reading, you are investing it!