Formatting page for images

Hello all. I’m new to the wordpress forums and I hope to receive help sometimes and then give help. However I need help on this occasion.

I have a website I am starting up and I am creating it from scratch and slowly incorporating it into the toolbox theme.

I’ve done some of main page(not in wordpress yet) but I’m am stumped on the recent work part of the site. Please don’t mind the fact that it’s probably not a perfect layout yet. I have added CSS3 Media queries to it so as your change the width of the window a bunch of things will change.

https://www.ambrelasweb.com/dev2

The RECENT WORK part of the site I have been thinking about for a while now and this will be my second site made into wordpress. I’m trying to make it so when you re-size the window and the images move down they remain centered? Does anyone have a snippet of code that can help me out, or know of where I can find some help?

The other part I was thinking about is how do I format that code so when the admin places images into the WISIWYG editor in wordpress they will format the way I want? (3 across?)

I know I can do

<section>
<article>
<img src=”the image here”>
</article>

<article>
<img src=”the image here”>
</article>

<article>
<img src=”the image here”>
</article>
</section>

to lay them out but then they cant be changed or controlled by the admin, or can they??

Any help on both these thoughts would be really appreciated.
Thank you in advance.