Previously: Getting started, community building, roundup
One of the recurring bits of advice from seasoned bloggers is the importance of graphics to relieve a wall of text. That's not bad advice, but if you exercise it incorrectly you do a disservice to your post!
On my site, I make an effort to use primarily screenshots - not only that, but screenshots that I personally have taken. I loathe using pictures from other sources in my posts because it makes it feel less like my work. Which doesn't mean I won't do it or that you shouldn't - it just means more work to properly credit the source. There's also the pesky reality that the original picture could be moved or taken down. Sometimes I will save and reupload the picture so it's hosted by my picasa album, but source the page I got it from.
But I'm getting away from my point, which is consistency and relevance. I said I like to use screenshots, which means that using non-game images like photographs and graphics happens only when necessary. It breaks the overall consistency of my blog, but sometimes you really need a picture of yourself in a Spongebob costume! (high five if you recall that) Then there's relevance. I could google the word "relevance" and pick the first clip art picture that comes up, but it would have NOTHING TO DO WITH THIS POST. I would be trying to force an unrelated picture into my post solely for the sake of having one. It would be completely at odds with the other images I keep on my blog. Frankly, in my opinion, doing this looks generic and unsophisticated.
Unless you can make random clip art your schtick, at least try to pick images that have something to do with your overall blog content and theme. If you use images that aren't yours, credit the source. Explain the purpose of the image, either with a caption or by putting it near an appropriate paragraph. Don't just put images willy-nilly in your posts because you feel like you need to have them. And for everyone's sake stay away from clip art unless it's absolutely necessary!
So this is probably more of a rant than actual advice. I'm sorry if you do this in your blog posts and it sounds like I'm complaining at you. I was reading a post earlier today that had some completely random pictures pulled from google and they destroyed the message. At first I thought they were ads! Then I spent way too long trying to figure out what they had to do with the paragraph they were closest to. Way too much work! Don't let your imagery detract from your blog posts!