Standard Infantry is tricky as there is no such thing. All of the major combatants of WW2 used quite a variety of differant classifications of foot troops. But however it is classified the classification usually just refers to the transportation employed ie:-
Infantry, Motorised Infantry, Armoured Infantry, Parachute (Airbourne Infantry).
All of the above were troops whose role was to fight on foot using small arms.
The basic organisation at this time was:
Squad > Platoon > Company > Battalion > Brigade > Division > Corps > Army
But when you get to Division or above you will get support arms of various types (eg artillery and recce elements) thrown in just to confuse the issue.
WW2 caused massive tactical advances in the use of the "specialist troops" such as pioneers, commando's and parachutists and libraries have been written on these units. Specialist troops such as flame thrower users in the US system (correct me if I'm mistaken American people) tended to be grouped together in a heavy weapons company within a standard battalion. Or a heavy weapon platoon within each company I forget which.
Sorry.
Good sources for a basic overview tend to be books written with wargamers in mind. They tend to have plenty of detail and emphasise the tactical reasoning for the existance of "unique" troop types.
Will
I'm basically doing some preliminary research on the major types of infantry, tanks and aircraft used in World War II. Aircraft is covered just by memory or scanning through some of my books. Being unfamiliar with the terrestrial details of World War II, I found a good site as far as detailed armour specs go, and checked out a book from the library to acquaint myself with the major types. Infantry however has proved to be one tough cookie. At first thought I took this to be the easier of the three groups, but so far all I could think of is standard infantry and bazooka teams. So questions are as follows:
And Hagar, I gotta give it to you. You're just better than phrasing searches than I am. 
(
) What, oh what would I do without Simviation... 
Like I said, I'm weak on the British Tanks...