Chinmaya Mission seems to be the most prolific in organized Hindu tempels. IMO it also seems to be the most modern and the easiest to learn from. I go to Chinmaya Mission Houston and its truly very deeps stuff.
http://www.chinmayamission.org/
The differences in different practices in Hinduism is usually because of different beliefs which stem from different parts of India. Imagine if India is like the US with different states, except in every state there is almost a different language and perhaps even a different script!
http://www.indolink.com/SFO/chinmSJC.html is in San Jose, should be close and those guys will give you THE best explanation.
And obviousely if worst comes to worst
http://www.google.com/search?hl=en&lr=&ie=UTF-8&q=Hinduism
Hinduism is really two things. Culture and then religion.
The cultural part includes festivals and such.
The religion part is however not really a religion, it can be more identified with a way of life.
First Hinduism tries to be completely free from obligation or blind followership.
Instead of "word of god" it is compromised of two things. One is a story called the Mahabharat in which a divine teacher (Lord Krishna) shows his friend in the midst of a civil war the thought process of action, inaction, and self unfoldment in short.
The next is a collection of vedas and scriptures that are thousands of years old on life, the mind, and self unfoldment.
A common misconception is that Hinduism has many gods and because of that is not monotheistic.
WRONG!
Hinduism does believe in ONE god, its precence however is undefined or more correctly, infinite.
The wise people who created the vedas however knew that prayer is one thing. Focus. Focusing your m ind and body to attain your goals and achieve your highest potential is key to anything. Hence forth they created different incarnations of god who are representative of a value or an aspect of life. Therefore when I am praying for wealth of knowledge I pray to one "god" because it allows me to focus it towards his aspect and henceforth my aspect in life. Think of it this way. If god came before you and asked you what you would want you would go wild asking for so many things. Now if a hindu god such as Saraswati came before you and you knew that she could help you with knowledge, then you know what you could ask for and you would be more specific as to what help you needed in knowledge.
Hinduism is all about organization of thought and focus. That is why focus is the essential quality pervading througout every hindu scripture.
hindunet.org is very good for in depth research on hinduism. Also the Chinmaya Mission in San Jose should be a good source of information as well.