Completely agree that Presto Music is an outstanding resource for classical music!
In addition, I recommend the classical review magazine Gramophone: Gramophone – classical music magazine, podcast and reviews | Gramophone
The main blog is free but with a paid subscription Gramophone has thousands of classical recording reviews going back a century!
I also recommend the streaming radio channel Accuradio: Classical - Listen to Free Radio Stations - AccuRadio
Accuradio does not stream in high-res but does have a wide variety of hundreds of free channels and sub-channels including a classical channel with 84 sub-channels listed and described. Since it is free it does have some commercials, but I don't find them intrusive all things considered. For desktop background listening it is quite enjoyable.

