What's a doujinshi?
Check here.

Who are Roy and Hawkeye?
Go here for that.

OMG! There're actually NON YAOI / HENTAI doujinshi?!?!
Yes, there is. Le gasp. And not only does het(erosexual) romance exist, there are also gag doujinshi and even general (with no pairings) ones. I kid you not!

Me wants! How can I buy some of them?
The easiest way for non Japan residents is to do extensive digging at conventions or stalk Ebay badly. Of course, there are other online shops and ways to get them. Take a look at the site section for links.

Would you scan a complete doujinshi for me?
Sorry, won't do. Apart from the fact that I'll sooner cut my legs off than hurting the spine of my doujinshi, I think scanning and sharing complete books is disrespectful to the author, since they get no profit from it.

I can't find RoyAi for my life, just RoyEd! *weeps*
Dig a little deeper. Usually, Ebay isn't of much help for (mostly) non-yaoi collectors, so it's possible you will need another source (specific shop, Yahoo Japans Auctions). Still, non-hentai RoyAi is relatively easy to find, compared to other het ships (for example Ed/Winry), so don't despair and keep looking!

But there's so little RoyAi compared to other ships...
Believe it or not, the RoyAi doujinshi fandom is quite rich and still in very good health. The percentage of het doujinshi against yaoi doujinshi is always very low for all shounen series, but RoyAi is without a doubt the most popular het pairing in Fullmetal Alchemist, and probably one of the most popular straight shounen couples (comparable to Athrun/Cagalli in Gundam SEED perhaps).

You look a little obsessed.
Why, yes I am.

That's all for now. Got a question not answered here? Email it to me.