Getting married is a very big step and a lifelong commitment. It is important you get to know them. The question is, as dating is not allowed in Islam, how to get to know a potential spouse?
What is a very important issue is that you chose someone who is compatible with you. Someone who is a good match and someone who cares about the same things that you do. It is extremely important to know what you want in a woman and what you want in a man. Many marriages fall apart these days because people simply do not know the answer to that question.
The man can visit her family and talk to her with her family there. You can also ask mutual friends about the person and their family. You can find out who their friends are, you know a lot about a person when you see who their friends are.
The main point is that the proper etiquette of Islam is followed but you can find out about the person and get to know them before them in Islam.