What is the best way and method to invite non-Muslims (Christians and Buddhists) to Islam, and are there specialized websites for teaching individual and group dawah?

Whoever wishes to call to Allah must base their call on insight, meaning knowledge of what they are calling to, the condition of the person being called, and the correct method for the truth to reach them. They must also proceed gradually in their call and be patient, seeking reward from Allah. They should utilize da'wah booklets and websites and consult scholars and callers to Allah.