Who founded your Religion, and where and when?
Sikhism is only religion which contains experience of 37 Great Devotees of God who have similar spiritual experience. Basically it is called Gurmat - The True Path.
The Path which evolves and dissolves then again evolves.
Kabir bring before us then Religious Scholars and False Religious practitioners starting to put their curtain of falsehood on it and Nanak again evolved it and process continues.
It is oldest and Newest Religion.
What is the main book of the teachings?
Sikhs follow Adi Granth as their leading scriptures as it is only scripture contain utmost truth because it is totally spiritual granth. No stress on any other subject like histories or bla bla. It is all about Spirit. How spirit comes what spirit is. Why we are here what is our work and so on.
What are some of the teachings?
> No Vice or Virtue
> Understand Yourself as in sikhism spirit is his part, worship yourself is understanding yourself
> live logically
> hukam(will of god) is above all
> learn and follow and keep on attaining spiritual wisdom first from external source, then from inside.
if you really need underlying truth then remember knowledge in Sikhism is somewhat which breaks all previous mentalities and start making your mind which could search inside you to there, and you know where
there is much more to tell....
Waheguru Ji Ka Khalsa
Waheguru Ji ki fateh