What format for a 28 page history quarterly?

If I'm not in the right place Mods, feel free to shift me to where I should go, as I'm not sure if this should be here or in self-publishing.

I'm an assistant County Historian in NYS, and a computer geek. A 28 page history quarterly has been published out of our office since 1946. We have about 800 subscribers across the US, plus they go in local stores. We PDF the file for the printer, then bulk mail.

Today I realized I forgot to put my brother on the mailing list, but figured I could just send him the PDF. Which made me think, why don't we put them on line for download? Dah. Some people might prefer it, the international genealogy people might like it. We might pick up a few new fans.

Being the resident computer geek it would be on me to do it, which I don't have a problem with I'm just not sure on the specs for something so short. Our Historian's Association has it's own website. Since I'm the webmaster I can sell/put a link through there but where else? Is that a smashwords type thing?

Thank you so much! Kindle, really? Even for only 28 pages? Cool! Never heard of WOWIO so I will check out that too. Thank you so much CaoPaux!

Yes, I'm wondering about formatting, since there are photographs or other images too.