When you do your research to begin blogging, you'll find all kinds of cool things that people do on their blogs. Unless their particular blogging platform has buttons for these effects, they used HTML or "hotmail" tags.
HTML tags must be enclosed with the little punctuation marks that look like "less than" and "greater than" marks: < and > . Remember those from math class? If they are not enclosed, you have an "open tag" and the HTML code won't work.
One tag that I was first fascinated with was the strikeout. The strikeout makes a word or phrase look like it has been crossed out. Here is an example:
You can also use the strikeout to cross items off of a list. Many bloggers will keep their summer reading list in the sidebar and cross out each title as they finish it. There are many great uses for the strikeout tag. To strikeout "ticked off" above, I click the edit html tab and type the line with the tag
Notice that the tags come immediately before and after the word or words you want them to change. Also notice that the ending tag has a "/" mark before "del". That slash mark is very important since it tells the computer to stop the action begun by the first tag.
Another tag that I have found useful is the center tag. I used this tag in the above example as well to center the line. This sets a phrase apart from the rest of the post and comes in extremely handy when quoting someone or another site. Simply enclose the word "center" with <> before and "/center" with <> afterwards.
Here are two useful sites that I found for teaching yourself some HTML tags. You can easily integrate these into your blogging for extra dramatic effect.
CDI's Comprehensive HTML Cross Reference
HTML tags chart from WebSource. Scroll down for the chart.
I highly recommend that you visit Blogging Basics 101 for more great HTML resources.
Another way to learn HTML codes is by writing your posts in compose mode (sometimes called WYSIWYG for "what you see is what you get") and study the HTML version to see what kinds of tags are used when you make a word boldface or a different color or make words into a link.