Standalone websites about my favourite composer tend to have a lot of the same basic biographical information, with varying degrees of detail, but are frequently less strong on the musical analysis. Public radio sites are better at the music, but less comprehensive overall.

• CBC Radio 2: Beethoven’s Greatest Hits (includes a must-listen podcast in which Bramwell Tovey, at the piano, walks us through all nine symphonies)
• BBC Radio 3: The Beethoven Experience (includes brief notes on the 32 piano sonatas)
• The Beethoven Reference Site
• Mad About Beethoven