Sat Sri Akal,
Welcome to the forum. I am also new to this forum ( Don't look at my enrolled date but number of posts lol) and even though I was born in a Sikh family, I was never a practicing Sikh. I didn't knew anything about Sikhism until the last one year and I am still learning and that exactly what Sikh stands for, A learner.
Describing Sikhism can be as complex as solving the mysteries of Universe and can be as easy as following your heart. Like I said, I am still a learner and don't wear turban, don't have beard. Even though these are essentials for a Sikh way of life, I will still be equal in the eyes of a Waheguru ( The perfect teacher or as people call GOD). I am learning my way towards living a Sikh way of life and the day I start doing it, I will be the most happy person on the planet.
Some terms that comes to mind when I say Sikhism and that is "Love", "peace", "Equality", "Honest Living", "tolerance", and above all "Love and not Fear of God" unlike what other religions say.
No offence to Any religion: But just something I think about and believe:
There are no Messengers in Sikhism, and some people say that its one of the reason that it can't be compared to Islam and Christianity. Let me tell you something. Who is a messenger? He is someone who conveys the message. Who is a Guru, A guru is someone who explain the message.
We all go to school, there are text books available, why you need a teacher as books are there and conveying the message of the author? I am sure you are smart enough to understand "Y". A teacher is there to guide you , teach you things that no one else can teach. Sikh guru's wrote their teachings in the holy book and we call it "Sri Guru Granth Sahib", the perfect Guru till eternity. Its not a book of laws and doesn't say what to do and what not to do.. Its a teaching and people who understand it will cross the bridge.
Not even sure if I have explained something.
I can give you some links but I won't as they don't explain Sikhism. As an outside you click on the link and the first thing most of the websites say is "5 essential K's of Sikhism", don't get me wrong they are utmost essentials but you first need to learn what Sikhism is and they you will be able to answer these questions yourself.
Anyway, I won't go through the details as there are other experts out there who will answer it, I don't want to say something that is not right.
Thanks
May waheguru bless you.