I'm so new to the blogging scene, I'm not sure I can come up with ten. And since I'm so new, I'm going to approach this from the point of a view as a blog reader!
- Images of books that aren't linked to something like Amazon or GoodReads. Pictures pull me in, I want to learn more about the books, give me a link!
- Light colored text on a light background or dark text on a dark background. I'm old and I have bad eyesight to boot. If I'm straining to read it, I'll move on.
- Too much happening on the page especially if it's moving/flashing. I'm visiting your blog read your review (or enter your contest). Let me focus on that.
- Oh, and if I'm leaving your site, have the link open a new tab (target="_blank") because I want to come back, browse around your blog some more and subscribe to future posts!