The basic requirements of Secure Nodes are:

Maintain a minimum of 42 ZEN in transparent address per node. Demonstrates the operator cares enough about ZenCash to own some.
Create and maintain a valid TLS certificate from a known Certificate Authority. This enabled encrypted data transport.
Run the node on a server with enough processor and memory so that it can meet a computational challenge. This protects against DDoS attacks.
Maintain a full copy of the ZenCash blockchain. This makes sure no UTXO’s  or commitments are lost.
Keep the node up and running at least 92% of the time.
3.5% of the ZenCash mining reward is distributed to all Secure Nodes which meet the requirements during each pay period.
https://blog.zensystem.io/secure-nodes-why-are-they-important/

You can find all informations here->
https://forum.zensystem.io/t/secure-node-tracking-and-payment-system-software-development-project-discussion/126/14
https://blockoperations.com/build-zencash-secure-node-part-1-prepare-vps/
https://blockoperations.com/build-zencash-secure-node-part-2-build-zen-node/
https://blockoperations.com/build-zencash-secure-node-part-2-5-test-tls-secnodetracker/
This one can be called simple.
https://medium.com/@jm9k/how-to-setup-up-a-zencash-node-a-guide-for-complete-noobs-d585216d289a