My knowledge of 40k lore is weak, but how hard can it be to get to grips with?

I command a regiment of cannon fodder, and have to lead them into suicidal missions for the glory of the Emperor. 

That's pretty much it, isn't it? All I need to do is research the weapons in play, an Imperial regiment's composition, and then boom, I'm good to go. 

If you need another body to make up the numbers, I'm willing and probably abled.

[hr]

Edit:

[img]http://wh40k.lexicanum.com/mediawiki/images/0/04/RegimentOrg.jpg[/img]

Well that seems simple enough. Where are the Guardsmen coming from? Lots of different planets? Or is there a main contributor?