The above video shows how to make JPG Thumbnails of PDFs posted to your WordPress website the old fashioned manual way.
We’ve got a handy post about a plugin that makes it a cinch- https://websitetology.com/word-press-plugins/new-easy-way-to-make-thumbnails-for-pdfs/

There are many reasons why you would want to do this. First and foremost, uploading PDFs using the basic WordPress uploader just provides a link to the document- without a way for your user to see what the PDF looks like.

The reason you are using PDF’s instead of a JPG is because PDFs, if created properly, are search engine friendly and handicap accessible. To make a PDF properly, it’s not made from a scan- it’s made from an document- so that you can highlight and copy text from the PDF. If you are making a PDF from a scan, make sure you use the “recognize text” function to perform Optical Character Recognition on your scan. It won’t be perfect, but it will be close.

JPG’ss are also not search engine friendly, whereas PDF’s are.

Creating a JPG preview of your PDF is easy and will give your website’s users a better experience.

WordPress Version 3.3, named for Sonny Stitts, released to the public.

The most important change in my humble opinion is that they finally ditched the 4 different options for uploading media. Now- with easier uploading file type detection – A single upload button allows Drag-and-Drop media uploads, and the media autosorts on the type of file- .mov is a video etc.

They’ve reworked the dashboard design with a new toolbar in the dashboard, combining the Admin Bar and admin header giving you quick access to the most important functions and  the new flyout menus, providing single-click access to any screen  without scrolling through long lists of options on your left side admin menu.

The new user experience options provide new feature pointers, helping users navigate new features and also help direct new users to basic functions that they need through the dashboard welcome area.

New iPad/Tablet support is included in the admin area, but I’ve not had a chance to look into it yet.

via Version 3.3 « WordPress Codex.

As always with new versions, make a complete backup of your installation before upgrading and be careful with custom themes.

Making a playable audio player used to mean you had to embed a Flash player or a Quicktime file into your website. Luckily, now there is a way to add a simple HTML5 code that will not only play the audio file, but will create a player that the user can control. You will want to use HTML5 over Flash because many of your readers will be using a mobile device, and not all mobile devices are flash-enabled. We will, however, create a Flash player as our fallback in case a browser cannot handle HTML5 in this tutorial. You can also use a Quicktime file as the fallback, but keep in mind you will have to convert the file to an .mov.

The HTML5 audio and video tags make embedding files easy, and eliminates the need for the embed and object tags. As easy as they are, however, they have a few quirks that we need to fix. Some browsers, like Firefox, can’t play .mp3 files through the player. However, Firefox can play .ogg files, which browsers like Google Chrome cannot play through the HTML5 audio tag. We’ll need to upload and embed both of these files. The browser will only display the audio file it can play, so there’s no need to worry about having two audio players in your post.

Here is the final code that we will be using. This will include 2 versions of the audio files (mp3 and ogg), as well as a flash player as the fallback for browsers or devices that can’t handle HTML5.

<audio controls="controls">
   <source src="yourURL.mp3" />
   <source src="yourURL.ogg" />
<!-- fallback -->
<embed type="application/x-shockwave-flash" flashvars="audioUrl=yourURL.mp3" src="http://www.google.com/reader/ui/3523697345-audio-player.swf" width="650? height="0? quality="best"></embed>
</audio>

If you prefer, you can simply add text as the fallback. Here is what this code will look like.

<audio controls="controls">
   <source src="yourURL.mp3" />
   <source src="yourURL.ogg" />
<!-- fallback -->
Your browser cannot handle HTML5.
</audio>

*Note: It is STRONGLY recommended that you use the Flash player as the fallback