Rickie, I'm not sure why some people are struggling. It might be that the difference in browsers or operating systems makes a difference (although I doubt that)
The following should work. There are two stages to this. Getting the info you'll need to make the link to your book and its cover, and inserting this into your signature. I find it easier to do all of the following in Notepad, and then copy it across to the signature block, rather than trying to edit it in the signature block.
To get the book's URLOpen the Amazon page of the book you're linking to. Copy the URL of the book's page. Make sure you only copy the info up to the ASIN. So for example, if your book was Divergent, you'd copy only the black part of this URL and leave out the blue part:
https://www.amazon.com/Divergent-Book-Trilogy-ebook/dp/B004WC07UK/ref=sr_1_1_twi_kin_1?s=books&ie=UTF8&qid=1538408879&sr=1-1&keywords=divergent To get the picture linkRight click on the book's image on Amazon and choose "copy image address". Depending on your browser, that might be phrased slightly differently.
Create the signatureGo to Profile > Forum Profile.
On that page, find the "Signature" field. This is where you'll be pasting the code.
Copy the following code:
[url= ][img height=125] [/img] [/url]
Then paste the book url after that first "=" where the x's are below:
[url= xxxxxxx ][img height=125] [/img] [/url]
Then paste the image address after the image height tag where the x's are below:
[url=https://www.amazon.com/yourbook/dp/ASIN/ ][img height=125] xxxxxxxxxx [/img] [/url]
Make sure that every opening square bracket has a closing square bracket. Make sure that you don't change the way the brackets are nested. I hope that works.
To do more than one book, just rinse and repeat, add the next one after the first. Don't put carriage returns between the lines of code or they'll appear below one another in your signature. You can space them out by adding spaces between the last "url" tag of a book, and the first "url" tag of the next book. Like this:
[url=book1link ][img height=125] image1link [/img] [/url]space[url=book2link][img height=125] image2link [/img] [/url]