Absolutely, there are several resources and methods for securely storing verifiable credentials and PII on IPFS:

1. IPFS Documentation: Begin with the official IPFS guide on file storage. It offers foundational knowledge on storing various data types on IPFS. Check it out here: Storing Files on IPFS.

2. Verifiable Credentials Data Model: This W3C specification outlines a standardized approach for expressing verifiable credentials. It's a crucial resource for understanding how to handle such data on IPFS. Learn more here.

3. Ceramic Network: This decentralized network built on IPFS specializes in managing verifiable credentials. It provides additional layers of security and verification suitable for sensitive data like PII. More information can be found here.

4. Zero-Knowledge Proofs (ZKPs): For privacy-focused storage of PII, consider leveraging ZKPs. They enable the verification of data without exposing the actual content, adding an extra layer of privacy to your IPFS storage strategy. Explore ZKPs here.

Always prioritize security and privacy when dealing with sensitive information on decentralized platforms like IPFS. These resources should give you a solid starting point for implementing your solution on IPFS.