[pdftex] elementary latex-pdflatex questions

[Haines Brown KB1GRM]

In a new installation of debian squeeze, the TeX package I installed 
was TeXlive 2009. This introduced a change from the default production 
of .dvi files to the production of .pdf. This left me unable to 
function, and I'm sorry to have to bring up some very elementary 
questions.

It seems that if I run the latex command on a .tex file I'll generate 
a .dvi file, and if I run pdflatex on it, I generate a .pdf file. 
However, I get inconsistent results. Is there a problem combining 
these commands? Is there a preferred sequence? For example, if I 
generate a .dvi with the latex command, I can not then subsequently 
create a .pdf with the pdflatex command. Even though there is an .aux 
file, the log has:

	No file test.aux.
	\openout1 = `test.aux'.

In choosing between .dvi and .pdf format, I have the impression that 
to print hard copy, a .dvi file is mandatory, and the .pdf is for 
transmitting formatted documents as on the web or submitting material 
for publication. I'd appreciate some commentse on the accuracy of 
this.

Since I primarily want to print hard copy, I'd like to make the latex 
command default and the pdflatex command an option. To make latex the 
default command, there's probably a statement I can put in my .emacs 
init file such as (setq TeX-command-default "LaTeX"), but I haven't 
been able to find it.

When I go to print the .dvi file witn C-c C-p, I get "No appropriate 
`dvi' file could be found" even though there's one in the directory 
holding the .tex file.

Where is the documentation that answers such questions? I've poured 
through some manuals, but they seem to skip questions such as this.

Haines Brown