Simplest way to get youtube videos to be saved locally on an iPad
You don't specify what web browser you use, but if you use FireFox a simple plugin like Easy You Tube Video Downloader may be just what you are looking for.

https://addons.mozilla.org/en-US/firefox/addon/easy-youtube-video-downl-10137/

For Chrome you can use the following: 
https://chrome.google.com/webstore/detail/save-your-videos/pipiejpiplliidbnncmckaljhhchoihc


Step 1: Find YouTube Video
Step 2 (Click 1): Click "Download" button
Step 3 (Click 2): Drag Downloaded video into iTunes, dropping on iPad icon
Step 4 (Click 3): Click "Sync" can be via USB or via WiFi
Step 5: Watch videos in the Videos app on iPad