It is best if you have a browser like FireFox which has tabbed browsing. In one tab, sign into your Amazon Associate account and select "Build Links". The select "Product link" and click on the "Build links"
icon. A new page will open where you can search for products. Just type in the search term as shown in the screenshot below:
Click go, and you will be taken to a list of relevant products. If you see a suitable product, click the "Get HTML"
icon.You will be given 3 choices - text and image, image only, and text only. Since this post is about using a book cover image only, click the "Image Only" radio button and wait for a new page to open. There, there will be an image of the book cover plus the HTML to display it. If you use that HTML, you will have to save the image to your blog server, which in the case of blogspot user, is not possible. I don't use own domain and host with a third party web host, but if you are doing that, perhaps you may be able to use the HTML generated by ticking "Image only" by saving it to the server of your web host, but I am in no position to confirm as I use only blogspot and have no access to Blogger's server.
If you use blogspot or custom channel where the blog is hosted by Blogger, there is still a way to do it. Copy the HTML and save it to NotePad. I will show the image of the HTML with the link (URL) to the Amazon Product highlighted in blue below (click on screenshot to enlarge):
Highlight the link, copy and paste it either in the same or different NotePad for future use. Now you need an image of the book cover. Press the Printscreen key and open a suitable photo editor like the very good and free Irfanview (click "BACK" button to get back to this page). Paste it into the photo editor and crop the book cover image. Save it into a suitable folder in your computer. I saved it in a specially created "Temporary" folder which I can easily find.
Actually, although I ticked the large image, for the book cover image I did for Digital Photography Articles, I actually didn't do it that way, but opened a new tab and went to http://amazon.com/ and made a search for "The Digital Photography Book" and printscreen there and pasted and dropped the image of the book cover as described above. This is because I wanted a larger image.
Now you will have to host the picture on the web somehow. You can use Blogger as described in the post Getting New Blogger to host your image for the profile, sidebar, etc. (click "BACK" button to get back to this page). You can also use Photobucket or other third party photo host. I have actually posted it to a special blog My photo store: The Digital Photography Book for hosting the image.
Now to create the book cover image link in the sidebar. I clicked "Add a Page Element" for the left sidebar in the Layout of the Dashboard, selected HTML/Javasript, then typed <a href="Amazon product URL" target="_blank"><img src="book cover image URL"></a> into the HTML/Javascript window where the Amazon product URL is the URL I mentioned (and highlighted in the screenshot) above. To make things clearer, I will put the actual HTML into the scroll box below:
<a href=""http://www.amazon.com/gp/redirect.html?ie=UTF8&location=http%3A%2F%2Fwww.amazon.com%2FDigital-Photography-Book-Scott-Kelby%2Fdp%2F032147404X%3Fie%3DUTF8%26s%3Dbooks%26qid%3D1176421784%26sr%3D8-1&tag=bloggerfordum-20&linkCode=ur2&camp=1789&creative=9325" target="_blank"><img alt="Digital Photography Book" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdg3-vzLT7anrczJVs5fHThe-BZdpn0m5ysTPyTM3rXKGRrnxrpf_87RQbM1jwkh3bjrPGEIYFbt7C5AZ8LvfDUy6CDHlmh3WrrxEgNfHKSYRE7LwDbK_cOMpVy-I3OTlWp3cGCSkIW482/s1600/The+Digital+Photography+Book.jpg"/></a>
with the Amazon product link (URL) highlighted in red.
