Books

Guides

• Cantonese as a Second Language: Issues, Experiences and Suggestions for Teaching and Learning

Speaking and Listening (Conversational)

• Complete Cantonese: Beginner to Intermediate Course. Comes with great reviews.
  
• Colloquial Cantonese: The Complete Course for Beginners, with audio available here for free.
  
• Learn to Speak Cantonese I: A Beginner’s Guide to Mastering Conversational Cantonese
  
• Learn to Speak Cantonese 2: An Upper Beginner’s Guide to Mastering Conversational Cantonese
  
• For Heritage speakers: The ABCs of Cantonese: Beginner’s to Intermediate Chinese for Heritage Speakers

Grammar

• Cantonese: A Comprehensive Grammar

For Children

• Daily Vocabulary Cantonese-English
  
• Dim Sum, Please!: A Bilingual English & Cantonese Children’s Book

Websites

• My Father Tongue, this seems to have been last updated in 2020, but there’s still some material on learning dialect in Singapore. They also focus on Hokkien, Hakka, and Teochew