Clomid questions

Sophie • I`m a teacher. My husband is a pharmacist. We have not used bc in 3 years...
So, I have heard this word and I have had some friends take it. What is it exactly? What side affects can you have? How long do you have to be trying to start taking it? Is it true that you have a higher chance to have twins with it? Can anyone take it or do you have to have an underlying condition? Please, tell me everything you know 😄