I hope I can help save my Blogger pals some time so here's the run down. Here's the way I figured it all out, maybe there is an easier way but it works and that's all I care about.
Step 1: Design a graphic, I chose one of my own pictures and edited it in Picasa. You can use free clip art or design something, just make sure you own or have permission to use it. I saved my finished graphic on my desktop.
Step 2: Go into your blogger dashboard, select "New Post" as if you are going to write a post. Upload your image from where ever you stored it. I don't know if this matters, but I didn't select to align my picture, e.g. "None" and chose a small size.
Step 3: After it uploads, click on the image and then select the "Hyperlink" button from your Blogger toolbar, next to the font color option. Insert your homepage or blog address, e.g. http://sippycupsandfingerprints.blogspot.com/
Step 4: This is the part that I didn't know existed, see all those hours, I was educating myself. At the top right hand side of your post window you will see two tabs, "Compose" and "Edit Html". Click on "Edit Html", now you will see your HTML code for your button. Select the code and "Copy".
Step 6: At the bottom of the first code you pasted, on a new line, paste the same code again. I have to word this out rather than actually type it, because the computer just reads it otherwise. I am not computer smart enough to code it correctly to show you the code.
Type a less than symbol, "textarea"without the quotations, then a geater than symbol, and at the very end of your pasted code type, a less than symbol, a /, "textarea"again without the quotations, and then a greater than symbol.
This will show your code in a scroll box beneath your button , so your readers can display your button on their own site. Click save and you will be ready to arrange this gadget where ever you like on your blog.
If you have any questions leave me a comment and I'll try to help you out the best of my pea-brain ability. Oh, and don't forget you can now display my button if you enjoy reading Sippycups and Fingerprints.