A way to enhance and improve the aesthetic presentation of your blogs is to utilise graphics as part of your presentation. Photoshop is an Adobe product that has pretty much become the industry standard for editing and managing static graphic files. Its a program I use and find to be absolutely invaluable even if all you want to do is re-size or optimise your image from a load time perspective, but it is more than possible to get a little bit artistic and produce some reasonably impressive images with just a little bit of training and some practice.
There are any number of tutorials online that you can tap into for free to learn the basics of Photoshop. Most people will find that Photoshop Elements is perfectly adequate for their needs but if you want to get really serious you may prefer to take a look at the full Photoshop CS4 package.
As an example, the image below was done with Photoshop Elements and only took about 30 to 40 minutes to produce.