Luckily, after uploading a photo on Facebook, Facebook gives you the option of rotating the photo. Just click the 90º arrow next to the photo.
My problem WAS uploading the photos to another online photo album (gardenguides.com-- a gardening blog). Even tho' I'd fix the orientation in Preview and save them with the correct orientation, when I uploaded them to gardenguides.com, they came out upside-down or sideways. I worked around it by first saving them in the correct orientation in Preview, then uploading them to Photobucket (a free online photo storage site). For some reason, Photobucket DOES keep them oriented exactly the way I have them saved.
THEN, once they are uploaded to Photobucket, I looked at one at a time, control+click and scrolled to the option of "Save this image." (In other words, I downloaded the photos I had just uploaded to Photobucket.) Then I took THOSE saved images and uploaded THEM to my gardenguides.com blog, where they came out right-side-up. It was a hassle, but it worked. Thankfully it was only 5 photos that I took incorrectly-- someone on here said to be sure from now on to hold your iPhone with the Home button on the right when taking pictures.
