I want to start a business with my friend, who is a French citizen. I am an Indian national and I have a very good business plan. After a lot of discussions we both agreed to start an SARL company. We will be making products in France and will be exporting them to other countries especially to middle-east countries. However, as I am an Indian, I want to know if there are any requirements or restrictions for me to be a partner with French citizen. Which visa can I get and how can I stay longer in France? Also, are there any chances that I can get citizenship so that I can spend maximum time on our exporting business?
Follow the link that was given by @audionuma. If you can't speak French, your French partner can read that and translate. It's basically all there.
As for citizenship, you need at least 5 years of continuous residency in France, prove stable means of income, a clean record, and integration into the society -- knowledge of the language, culture, history. This last part is a bit vague, even in the official text, but let's assume that if after 5 years in France you still need your French friend to help you do the application, you probably won't get it. But depending on where you apply, your mileage will vary greatly.