Starting off it seems that setting up a general partnership would be a good start.
Well, first of all, the General Partnership is a BAD start to begin with. NO ONE should enter a General Partnership; it should have been outlawed. You're better off with an LLC or a Corp.
Are there any requirements or procedures to create a partnership with a non-US citizen?
Short answer: No, as far as the Secretary of State of California goes, anyone can create a partnership or LLC or corporation. As long as the entity pays the fees and the Franchise Tax, that's all that the Secretary of State cares about.
Long answer: This issue can be quite complex due to the number of government agencies that may have jurisdiction over the individual, the exact status of the individual, and the exact nature of the business. The issue can be more complex due to the fact that an Internet business' worker can LIVE and WORK anywhere on earth yet can generate income from EVERYWHERE on earth, including the US.
First of all, "Non-US citizens" can be further sub-categorized as:
* Resident Alien: he has a US Green Card and may live or work in the US
* Non-Resident Alien: he does not hold a US Green Card but has a US work visa
* "Non-Resident Non-Alien": he only has a visiting visa and does not plan to live or work in the US
Some issues to consider:
* Does he plan to LIVE and WORK in the US? or simply lives and works in his own country?
* Does the income of this Internet business come from the US? or from foreign countries?
* Where is the PRINCIPAL place of business? office?
* Does this business involve national sensitive material?
* Does this business include the sale of GOODS?
* Does this business include the sale of SECURITIES?
* Does this business include the sale of INSURANCE policies?
Depending on the answers to the above, there may be further consideration of applicable requirements and procedures, and a number of US and State agencies will have to get involved.
Of course, as far as the IRS goes, if the individual is a "non-resident non-alien" then he does not have to pay US personal income tax. Anyone else will have to pay US personal income tax. And of course the partnership/corporation still has to pay US corporate income tax.
