Permissability on writing saving books and investment website suggestions


Is it permissable for a person to write a book and guide the audience on where they can get free information on shares. Audience is mainly non musims but muslims will be able to purchase this book as well. The book does not mention advice on individual shares or funds, just websites where a person can get free share information. Would the sin be on the author if the reader then bought a non sharia compliant share from the website suggested.
Pls kindly confirm