Here are 3 blogs I highly recommend. Do you know of some others I’ve missed? I’d love to know about them! Enjoy!
Abe Mamet’s blog documenting his research into Julius Watkins and more; this includes links to some fantastic videos and other information:
https://jazzrefrenchhorn.wordpress.com/
John Ericson’s very popular blog covering many different topics:
Jeff Agrell’s great blog, also covering various topics; of interest especially to classically oriented players wanting to improvise:
https://horninsights.wordpress.com/