OT: User-friendly /bin/sh

[Bob Bernstein <poobah%ruptured-duck.com@localhost>]

*** Mandatory Trigger Warning /begin ***
Brain-dead noobie post dead ahead!
*** Mandatory Trigger Warning /end ***

I have learned the hard way not to mess with the shell superuser 
is supposed to use. I rarely go to su, but it would be pleasing 
if, when I do, I had two features available from the shell: 
filename completion, and some sort of command history and 
recall.

Can some Good Samaritan please point me to a HOW-TO that would 
provide the needed basic instructions?

Thank you.

--
Man is essentially a dreamer, wakened sometimes for a
moment by some peculiarly obtrusive element in the outer
world, but lapsing again quickly into the happy somnolence
of imagination.
                                    Russell