There are not as many Cantonese learning resources as Mandarin, but some websites include CC-Canto, Hong Kong Cantonese Learning, the Hong Kong Lexical List, Learn Cantonese, Omniglot, the Ottawa Chinese Language School, Trip Savvy, and WikiTravel.
Drops is the only app I’ve seen (besides this one) that teaches both Cantonese and Mandarin.
The Dim Sum Field Guide is an extensive illustrated collection of dim sum, and A Little Tea Book discusses varieties of tea (not just Chinese) and tips on tea preparation. Fuchsia Dunlop has written on various regional Chinese cuisines.
My favorites are cookbook-memoirs written with an Asian-American perspective, including SoCal-based The Boba Book, San Franciscans Mr. Jiu’s in Chinatown and The Mission Chinese Cookbook, Midwestern Chinese Soul Food, and New Yorkers Grace Young, Chinese Soul Food, The Nom Wah Cookbook, and Xi’an Famous Foods.