Short answer
Start with the Quran in a translation you understand, and a short biography of the Prophet ﷺ. Then read a simple book on Islamic belief and practice, and ask a knowledgeable local imam or teacher. This website offers the Quran, hadith with grades, fiqh and answers on these pages.
The fuller answer
Good starting points are the Quran with translation and short commentary, a book on the life of the Prophet ﷺ, and a collection of authentic hadith such as the Forty Hadith of an-Nawawi. Choose books by recognised scholars and be careful with websites that attack or defend without sources.
Do not judge Islam only by the news or by the behaviour of some Muslims. Visiting a mosque, attending an open day or meeting Muslim neighbours is often the best way to learn. Ask questions: Muslims are usually happy to explain.
This answer follows the mainstream Sunni understanding and is general learning, not a fatwa. Where Muslims differ, the answer says so. Have a question of your own? Write to us.