Update README.htm

Author: Jason Kridner

README.htm

@@ -418,27 +418,23 @@ <h2 id="hardware">Hardware documentation</h2>
 
    <h2 id="books">Books</h2>
 <p>For a complete list of books on BeagleBone, see
-<a href="https://beagleboard.org/books">beagleboard.org/books</a>.</p>
+<a href="https://beagleboard.org/books" class="external">beagleboard.org/books</a>.</p>
 <div style="display:table;"><div style="display:table-cell;padding:10px;">
-<iframe style="width:120px;height:240px;marginwidth:0;marginheight:0;" frameborder="0" src="https://bit.ly/2rwqa3e">
-</iframe>
+<a href="https://bbb.io/bad-to-the-bone"><img style="width:98px;height:95px;" src="Docs/images/bad-to-the-bone.jpg" /></a>
 </div><div style="display:table-cell;padding:10px;">
-<iframe style="width:120px;height:240px;marginwidth:0;marginheight:0;" frameborder="0" src="https://bit.ly/2rwp6ME">
-</iframe>
+<a href="https://bbb.io/cookbook"><img style="width:98px;height:95px;" src="Docs/images/beaglebone-cookbook.jpg" /></a>
 </div><div style="display:table-cell;padding:10px;">
-<iframe style="width:120px;height:240px;marginwidth:0;marginheight:0;" frameborder="0" src="https://bit.ly/2rwp6ME">
-</iframe>
+<a href="https://bbb.io/ebb"><img style="width:98px;height:95px;" src="Docs/images/exploring-beaglebone.jpg" /></a>
 </div><div style="display:table-cell;padding:10px;">
-<iframe style="width:120px;height:240px;marginwidth:0;marginheight:0;" frameborder="0" src="https://bit.ly/2qcPKq5">
-</iframe>
+<a href="https://bbb.io/elp"><img style="width:98px;height:95px;" src="Docs/images/embedded-linux-primer.jpg" /></a>
 </div></div>
-<h3>Bad to the Bone</h3>
+<h3><a href="https://bbb.io/bad-to-the-bone" class="external">Bad to the Bone</a></h3>
 <p>Perfect for high-school seniors or freshman univerisity level text, consider using "Bad to the Bone"</p>
-<h3>BeagleBone Cookbook</h3>
+<h3><a href="https://bbb.io/cookbook" class="external">BeagleBone Cookbook</a></h3>
 <p>A lighter treatment suitable for a bit broader audience without the backgrounders on
     programming and electronics, consider "BeagleBone Cookbook"
 </p>
-<h3>Exploring BeagleBone and Embedded Linux Primer</h3>
+<h3><a href="https://bbb.io/ebb" class="external">Exploring BeagleBone</a> and <a href="https://bbb.io/elp" class="external">Embedded Linux Primer</a></h3>
 <p>To take things to the next level of detail, consider "Exploring BeagleBone"
     which can be considered the missing software manual and utilize
     "Embedded Linux Primer" as a companion textbook to provide a strong