How to go about handing my notice in at work?

Any advice would help. I'm looking to hand my notice in at work. I work for two people but they have a boss over them who in turn would be my boss i. e. someone who I would go to if I have problems etc. I am handing in my notice to HR and to him. As I work for these two other people would I be expected to let them know or would my boss (manager) do that for me? I don't really want to have a conversation with these two people before I do it as I am set on leaving but want to try and be as professional as I possibly can over the situation.

How to go about handing my notice in at work?
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