Thanks, that is a big help. I thought that the 3rd icon from the left was for bookmarks but I couldn't get it to work. Turns out it was because I was in "Text Reflow" mode, which seems to be a way to more easily read text, kind of like "article" mode in a magazine. But the Bookmark icon doesn't seem to do anything in that mode.
As far as Text Reflow mode, I like it. I kind of stumbled into it and have it mostly figured out. It does not display images or diagrams, which is good to know. As with anything else in the program, you have to play around and try things, but even that doesn't work sometimes if you press something and nothing appears to happen.
Thanks again for the help.