How to transfer bitcoins from a wallet to an exchange?

As a cryptocurrency enthusiast, I'm interested in understanding the process of transferring bitcoins from a personal wallet to a cryptocurrency exchange. Could you please elaborate on the steps involved in this process? I'm specifically curious about the necessary preparations, such as ensuring my wallet is compatible with the exchange, as well as the actual transfer process, including any fees involved and the estimated timeline. Additionally, I'd like to know if there are any security measures I should take to ensure the safety of my bitcoins during the transfer. Your insight into this process would be greatly appreciated.