If you haven't already, I recommend checking out Seanbud's Map of the Week video reviews, which you can find on his youtube channel https://www.youtube.com/user/TheSeanbud. It should give you a general idea on how to play process and viaduct on every class.

Other than that, could you be more specific? Are you having trouble with midfights, holding chokes, trying to not die in pushes/stalemates? etc.

http://www.youtube.com/user/TF2Povs

http://www.youtube.com/playlist?list=PLD098F81F2CA74F00

http://www.youtube.com/watch?v=Lh6huINtf3g

http://www.youtube.com/watch?v=iq0sAL8uaMY

Thanks for these links, there's definitely some good stuff here.

I guess what I'm specifically looking for is actual STV footage that I can analyze with my team.

We are most definitely having trouble with everything you've mentioned.

Although comparing your team's play to high level play isn't always the best idea, here's a link to a package of all the STV demos of ESEA S12 Lan. http://teamfortress.tv/forum/thread/2565-esea-s12-lan-stv-package. You can take a look at how the teams are playing the maps and try to come up with some general ideas on how to approach each map.

Additionally, you can ask some ESEA-O/ESEA-IM teams to give you a demo of one of their scrims, then watch it and try to understand that.

Even though you may feel like you aren't capable of understanding your own play, try watching your own STV demos and ask yourself:
"Why did we lose that?"
"Why did my roamer die there?"
"How are they getting an advantage in this fight?"

Just re-watch certain fights over and over until you feel like you understand what's happening.

Or check the esea site, there's stv demos for download for all official maps.