I would suggest using the "cheats" link to the side of the article editor.
But as far as I know, all you have to do is upload the pictures, cut and paste [pic (your picture's name)] three times without pressing enter to have 3 side by side (given, of course, that they're not too big.)
My best advice for those of you who are starting out writing articles is to write a few practice ones to start (but DON'T submit them.) You can keep them saved, preview them to see how they look, and then keep on going back and re-working them. Then pick the one you like best and submit it.
Also, don't just write an article for writing's sake. Wait till you have the perfect inspiration. My last article on Full House was conceived while I was in the shower. For whatever reason, I was thinking about a message I had gotten from Candace a little while back, and then that reminded me of how I had just seen Jodie a few nights earlier on Pants Off Dance Off, and from there I got the idea to use what knowledge I'd already gained and do further research, and what developed was a fairly decent article, if I do say so myself.
And like Knites has offered, I'm glad to volunteer my services as a proofreader/editor.