I recommended it to wasabi, and I'll recommend it here again --watching Trump will level up your game immensely. He streams on Twitch, but I choose to watch the edited streams when he posts them to his youtube channel. He does arena runs, constructed decks (building decks from the best cards), and free to play decks (building decks from the ground up and crafting cards from earned gold along the way), and all while explaining his thought process, choices, and (usually) making the best plays with the most value. I learned A LOT from his channel regarding arena and learning to pick the best cards (which aren't necessarily the best cards for other style games, like ranked constructed).
Youtube channel:
https://www.youtube.com/user/TrumpSC
Force Strategy Gaming also has some good Hearthstone videos, although they don't cater specifically to Hearthstone. They're good about finding good decks online (usually decks used by high level/champion players), putting them into practice, and explaining how the deck works during play.
Youtube channel:
https://www.youtube.com/user/ForceSC2strategy
Another good player is Hafu, although she doesn't talk about her thought process as much as Trump does. She's still a solid player you can learn from, though.
Youtube channel:
https://www.youtube.com/user/itshafu/
If you want to keep it interesting, there's a guy named TotalBiscuit who does a lot of gimmick and fun decks, and he explains his deck builds and thought process as he plays ranked games with them. He's not specifically a Hearthstone player either, though, so you'll have to search out Hearthstone videos in his video feed. Great player, though.
Youtube channel:
https://www.youtube.com/user/TotalHalibut
Now lastly, ESGN has Fight Nights that consist of tons of games (Hearthstone being one of them). This is actually nice because there's a host who knows what he's commentating on, and it's high level players grouping up in teams to face off over a myriad of decks. A player from each team usually hosts and commentates when they're not playing, so you also get another high level view of what's going on. It sucks that I read ESGN is folding, but there's still great Hearthstone matches to learn from on their channel.
Youtube channel:
https://www.youtube.com/user/esgn
A really good Fight Night from ESGN: