Reddit mentions of Know Your Islam

Know Your Islam by Yousuf N. Lalljee is an excellent resource for learning the basic practices in Shia Islam. Try to pick up a copy if you can.

1. Yes Sharia is recognized by the shia, however I advise you to select a marja and direct your specific sharia/fiqh questions towards him. Ayatollah Sistani has a pretty available website and you can even send in and ask specific questions.
   
   
2. I don't think that it is expressly a sin to not go to a mosque or hussenia in the way that it is a sin to skip your prayers or not fast in Ramadan. However, the sense of community and exposing yourself to lectures/majalis can be very important for spiritual growth, and is important. At least it has been in my experience.
   
   
3. It is absolutely okay to visit a Sunni mosque. There is no restriction in shia islam against visiting a sunni mosque. Depending on the Sunni mosque, they might not be receptive to you, but I have never experienced this.
   
   
4. My saturday school used this book. http://www.amazon.com/Know-Your-Islam-Yousuf-Lalljee/dp/0940368021 Its pretty basic. A quick google search for "Shia History English Stories" gave me this site http://www.ghadeer.org/english/default.html. It has some history its not terribly extensive, but usually googling will get you a good amount of information.
   
   You can also google a topic and the name of a scholar. In my opinion Ammar Nakshwani and Hasnain Rajabali are reliable and straightforward. https://www.google.com/search?q=hasnain+rajabali&oq=hasnain+rajabali&aqs=chrome..69i57j0l5.3207j0j7&sourceid=chrome&espv=210&es_sm=91&ie=UTF-8
   
   
5. I don't know, I don't speak arabic. Sorry.
   
   
6. The specific months of Mourning are Muharram and Safar and the first 8 days of Rabi-ul-Awwal. You will find differences among shia's based on the culture they come from. Inconsistencies between the methods of mourning do not mean one is more correct than the other. This calendar has specific dates and events: http://www.al-khoei.org/OnlineServices/CalendarEvents.aspx
   
   
7. There isn't that much of a difference but I don't know a ton about sunni prayers so I don't feel qualified to outline them for you.
   
   Feel free to send me any questions you have. Just know that I AM NOT EVEN REMOTELY A SCHOLAR. I'm just someone that tries to be shia.