I read to my preschooler about 30 minutes a day, but he'd be fine with much more time reading! My 6yo went through a stage about a year ago when he never wanted to read, which was torture for me. Luckily, The Magic Treehouse revived his interest in books and he's spent hours reading that series. I hope I can find something else that he'll enjoy as much.
The Magic Treehouse series are great! My now 3rd grader loved those books in first grade. A good follow up series to those are the "Who/What Was/Is" series. They teach a lot about history and are easy to read. My 3rd grader is on the last Harry Potter books and is whipping through the Percy Jackson series (and other series by Rick Roirdan). Good for when your guy gets a little older!
My oldest LOVES reading, and usually reads about 2 hours a night! I struggle to keep fresh books in the house for him to read. My second child HATES reading (so sad!), so it is a struggle to get her to read her 20 min of reading required by her school. I purposely send all my kids to bed early so they have some built in reading time. I spend about 30 min reading to my preschooler and toddler.
My boys (3rd and 2nd grade) are required to read 20 min each night. My oldest loves to read and stays up late at night reading. My younger guy hates reading. I have to set the timer for him each night so he can get his 20 min in. My preschooler is starting to read so we find time to read during the day or at night before bed.
My two children are required to read 20 minutes a night for school, but even if they were not required to, they would still read for fun. We don't allow any ipads or tvs in their bedrooms so if they are not tired when it is bedtime, they turn to books. Which I think is great!
My third grader is required to read 15 minutes per night and write up a summary of what he's read. He finally has started enjoying reading so he will also do some reading just for fun before bed. My fifth grader is a voracious reader and reads well beyond the required 45 minutes of reading per day. He enjoys reading books on his kindle before going to sleep at night and with the built in screen light it is perfect for reading in the dark.
We have an insanely long bedtime routine that involves reading three books together. As my daughter has gotten older, the books have gotten longer, but we still read at least three. I hope my daughter's enthusiasm sticks for when she is able to read the books by herself.