1) Go to your 'dashboard'
2) Click 'Design' under your blog
3) Under the 'Page Elements' tab, click add gadget where you want a gadget
4) Select the add HTML
5) Copy and paste the text below into an HTML
<marquee direction="up" width="200" onmouseover="this.stop()" scrollamount="5" onmouseout="this.start()" height="400" align="center">
<a href="http://clarissadraper.blogspot.com/" target="_blank"><img src="http://lh6.ggpht.com/_ED_xmanimDQ/S89LMEL-GXI/AAAAAAAAAGM/gEI3YBlF4Q8/LTTV.JPG" /></a>
You'll notice in red some numbers. You can change those if you like to make the width of the scroll bar wider or taller depending on the size of your sidebar.
I put my button as one of the buttons for demonstration. I hope you keep it but you don't have to.
6) Visit blogs and where it says "Take my button" take the code and place it between the </center> and the </marquee>
If you have any questions, you can always leave a comment or email me and I'll help you through it.