Not sleeping well is a challenge, because WE get exhausted and need a break.
A routine helps. If you establish a good bed-time routine and there are no other underlying problems, this should work. But it takes time and persistence. Also, observe what happens anyway, you may already have some sort of routine in place without realising, that you can enhance.
Some things to focus on:
1) Avoid exposure to sources of light after about 6 pm (or earlier, if you want an earlier bedtime). That means no TV, DEFINITELY no computer, game console, ebook reader or similar. If you have dimmer switches, drop the light level a little. Or turn off the overhead fluorescents and put on a floor lamp instead.
2) Early dinner then bath. Warm bath. Towel him dry afterwards, have a bathtime routine. We used to towel dry the kids, put powder on them, help them dress in their pyjamas.
3) Snuggle in bed with a book - let them read with a bed lamp or have a night light (I know, I said reduce light sources but a night light is important for some kids). Read a book together.
4) Kiss the child goodnight then leave the room.
Something also to avoid - any games that are stimulating. In other words, avoid boisterous games before bedtime. No running, no jumping, no tickle games. C A L M...
The above is not going to work perfectly right away. But it's a start. You might need more books, for example, then begin to wean back on the number of books. Or choose books which are a little more advanced than he would read himself. I remember my nephew read "Little House on the Prairie" when he was 5 years old. If the book is read to him, it is easier to increase the intellectual level a little. Go for children's classics but do make sure you read them well. Put expression into it, enjoy it as much as you can. The slightly higher language level will stimulate the child academically (a good stimulation before bedtime) but mostly, will speed up his going to sleep. You will work out with trial and error, what level works for your child. If he falls asleep while you're reading, that is great!
My sister used to read Winnie-the-Pooh to her son from infancy. I thought she was nuts. But he grew up loving those books and now reads them to his own kids.
Marg