How can protect all privacy from someone that needs to use my Mac?

Question

A friend of mine is going to stay here for two days, and I am sure he will need to ask me to use the Mac (and PC) in the study room. (which will be tons of work to move them and no matter where they are moved, the friend for sure will ask for use of a computer).

In such case, what is the best way to protect my privacy, so that he won't be able to look at my Documents folder, Photos folder, etc, and all of my Firefox, Chrome, Safari's History, Bookmarks, and Stored Passwords?

I can create a temporary account, I think, and log in using that tmp account, but will that protect looking at my default user folders on hard disk, and also, the Safari / Firefox / Chrome etc were installed so that they can be used by all users, so do I also need to remove all those History, Bookmarks, Stored Passwords, on each browser? (and it is not good to remove the bookmarks and stored passwords because I may need them later).

Is there a better way?