SSD and HDD in Mac mini

Hi there.

First...If I'll put an SSD in the Mac mini...are the fans going to work correctly? I've heard that they will run at full speed all the time.Is this true?

Secondly...Can I add a 2nd HDD ??

Also, I want to know if these upgrades can be made easy.(I mean...no aditional cables or glue).

Thank you very much!