How to collect research data online?

What are the reliable ways through which I can collect research data online? I thought creating online surveys and sending personalized emails to the respondents would do the job best, but then I really don’t know how to do it. Also, I wanted to get it clarified if online data collection is even ethical? Because the authenticity of data is seen vulnerable in online data collection in many cases, I’m doubtful. Please advise something. Thanks pals in advance!