Viswanathan Jayamohan's Blog - Spirituality: Atmopadesa Satakam - Sree Narayana Guru -
blogspot.com/2013/07/ atmopadesa-satakam-sree- narayana-guru_27.html?m=1
Atmopadesa-satakam by Sreenarayana Guru is an interesting introduction to philosophy.
This link takes you to verse by verse English translation of the work.
Many including Nityachaitanya Yati have written detailed commentaries.
M G Warrier