Update courses.md

Author: shannona

_pages/courses.md

@@ -24,11 +24,23 @@ Our original "Learning ... from the Command Line" course offers an entire curric
 
 (This course is currently outdated; the foundation is solid but current techs are not covered; contact [us](mailto:team@blockchaincommons.com) if you'd like to support its update.)
 
-* **GitHub Course:** [https://github.com/BlockchainCommons/Learning-Bitcoin-from-the-Command-Line/blob/master/README.md](https://github.com/BlockchainCommons/Learning-Bitcoin-from-the-Command-Line/blob/master/README.md)
+* **GitHub Course:** [Learning-Bitcoin-from-the-Command-Line](https://github.com/BlockchainCommons/Learning-Bitcoin-from-the-Command-Line/blob/master/README.md)
 * **Translations:** [Portuguese](https://github.com/BlockchainCommons/Learning-Bitcoin-from-the-Command-Line/tree/master/pt#readme), [Spanish](https://github.com/BlockchainCommons/Learning-Bitcoin-from-the-Command-Line/blob/master/es/README.md)
 * **Last Updated:** 2022
 
 ## Learning FROST from the Command Line
 
+<a href="https://learningfrost.blockchaincommons.com/"><img src="https://github.com/BlockchainCommons/Learning-FROST-from-the-Command-Line/blob/main/images/learningfrost-screen.jpg" style="float: left; border: 1px solid white !important; width: 350px; margin-right: 12px;"></a>
+
+Our "Learning FROST" explains what FROST is and why you'd want to use it for signing over traditional signing systems such as multisig. It then provides a hands-on tutorial for signing with the ZF FROST tools, and also for integrating FROST signing with Bitcoin transactions.
+
+* **Online Course:** [learningfrost.blockchaincommons.com](ttps://learningfrost.blockchaincommons.com/)
+* **Last Updated:** 2025
+
 ## Smart Custody
 
+SmartCustody describes “The use of advanced cryptographic tools to improve the care, maintenance, control, and protection of digital assets.” The original book is user-oriented but a number of articles added since its publication support developers in creating smart-custody systems.
+
+* **Web Site:** [smartcustody.com](https://www.smartcustody.com/)
+* **PDF Book:** [194-page book](https://bit.ly/SmartCustodyBookV101)
+* **Last Updated:** 2019 (book), 2024 (articles)