Important factors to consider when deciding which books to read are interest, level, and overall objective. You should begin by thinking about what you enjoy reading in your language. Are there particular genres, authors or types of books you like?
Lower-level learners are often encouraged to start with children’s books. However, if this isn’t of interest then there are other options. For example, comic books are a good alternative and are very popular among adults. Also, you can find adapted or graded books to suit your specific level.
Choosing a book at the correct level is key. Books that are too easy or too difficult are not going to hold your interest for long and you won’t learn much. If you are unsure of your level, then you can take a quick online level test for confirmation.
Whatever books you read will also depend on your goal. For example, there are many classic novels which are written in old English, which are good if you’re studying English literature. However, for someone just looking to improve their day-to-day vocabulary, modern books might be more appropriate.