If you like the look and personalization of having a signature like this:
at the end of your posts, try this:
Go to My Live Signature. Click on "proceed" and "create signature".
You can then either click on creating a new signature, or uploading a scanned image of your real signature. Let My Live Signature walk you through the steps to create a signature you are happy with. If you create one with their fonts, you can chose the look, size, slant, etc.
You can save the final product as an image to your hard drive by right clicking on the signature and choosing "save image as", naming it and placing it on your computer where you see fit. Or you can click on "Want to use this signature?" at the end of your process and it will create HTML code for you to place on your blog.
If you decide to use their HTML, copy it, then go into blogger. Click on "Settings" in your blog dashboard, and then "formatting". Scroll down to the bottom where it says "post template." Paste the code you just copied into that template. When you next go to make a new post, that code will already be in it. Just make sure you type your post *above* the code, or your signature will come first in your post.
If you would rather host your own image in a place like Photobucket, right click on the signature image provided by My Live Signature like I described above, save it to your computer, then upload to your hosting place. Copy the HTML they give you, then place this code in the "post template" section under "settings" in blogger like described in the last paragraph: (replace parenthesis with <> )