Preloading Command/Parameter Recall in .emacs?

[Siegfried Heintze]

There are some might long commands, search strings and file names I use
frequently and I'm getting might tired of typing them in all the time.

How can I preload the command/parameter recal for the various command and
parameter prompts in my .emacs file? I'm particularly intersted in the find
file command (C-x C-f).