So im laying out a services page for a website (general service information), and there are a few primary services, and a larger number of secondary services (with the majority of those, less important than the minority).

My question is, Which way is best to structure the HTML code that contains this information?

This is what I have so far:

header
logo
nav

div #main
section
h1 - service one title
p

section
h1 - service two title
p

section
h1 - service three title
p


section .secondaryservices

article
h2 - secondary service one title (ie: service four)
p

article
h2 - secondary service two title (ie: service five)
p


section .tertiaryservices

article
h3 - tertiary service one title (ie: service six)
p


article
h3 - tertiary service two title (ie: service seven)
p


article
h3 - tertiary service three title (ie: service eight)
p

article
h3 - tertiary service four title (ie: service nine)
p
footer



Now, is this correct?

Or should each of the Primary Services (ie the top three sections), have a single article inside them too? ...to hold the service information? Matching the layout/structure of the secondary and tertiary services

Is an article always needed, or is it oay to sometimes place content inside just a section? If so, when? As per above?

I know this is probably a small matter, and may not matter to most, but im really quite into making sure things are done as correctly as possible, and still adjusting to HTML5 from HTML4/XHTML so would appreciate any advice.

Thanks guys!