You guys need to SEARCH the FORUMS before posting. You also need to read the forums. There are several posts in the Tutorials forum that tells you just what you wanted.
Now, there should be no problem with messing up the template. All you have to do is make a backup. I'm sure there are also places you can download it again from if you mess it up.
Willmaker,
Go in your templates folder and find a file named similar to "overall_header". The extension is either .tpl or .php, I forget. Anyway, go in that file and find where you want to put it. This is guess work on your end, so there is no reason to post it in the support. Either put it after the logo or somewhere near where you think.
If you have any other problems, say so.