I purchased Storm Structure 101 in 2012 I believe and have watched it close to two dozen times. I've definitely gained a little something out of each viewing. Definitely worth it for beginners .
I happen to be going on my first ever chase this year in May, so I'm super super excited!! If I am able to bag a tornado while I'm out there, its a total bonus. i'll just be happy to see a supercell thunderstorm rotating and a wall cloud. MY expectations going in are 1) lots of driving, and 2) very little chance of actually seeing a tornado. I'm bein realistic.
One of the things I found interesting, is if you look up the convective outlook for various storms in videos you watch, it gives you an idea of what the forcasters were thinking.