If you're blogging on the Wordpress platform, composing your posts in MS Word, copying and pasting them to the Add New Post window, this carries over encoding that makes your post look funky sometimes when you hit publish. To avoid this, use something like BBEdit, TextEdit (included on Macs), or another notepad type of software. I know some folks use blog editors like Ecto as well. This works too.
If you have composed posts in MS Word in the past, go back to those post in Wordpress, select all (Crtl + A or Cmd + A) and click the Remove Formatting button to clean it up (the button looks like a white eraser).
Need help? Shoot me an email at chel [at] chelpixie [dot] com.