For WordPress:
1) Once you're signed into your blog, click the Presentation tab, then choose the Widgets option.
2) Drag the Text box up to your sidebar, then paste the code into it. If you'd like the code centered, then put <.center.> (without the periods) right before the code.
3) Move the new Text box wherever you'd like it on the sidebar, then click Save.
For Blogger:
1) Once you're signed into Blogger, go to the Template Tab. Make sure you're under the Page Elements subcategory.
2) Click Add a Page Element and choose the HTML/Javascript Option.
3) A window will pop up. Paste the code into the box. If you'd like it centered, type in <.center.> (without the periods) before the code.
4) Move the HTML box wherever you want it on your sidebar, then click Save.