Starting A Business with no office address

Thanks for creating this board. I need some advice on based on the following circumstance.

-I would like to set up a business that will allow me to practice my specialization as a consultant however there will also be intellectual (training) related products that I will be marketing using the business name

-Someone is also interested in partnering with me in through the above endeavor as his key role will be both intellectual and product development, delivery partner.

-I also plan to carry thru an international distributor agreement a training product from the US

-Since this is a startup we wont be having an office yet as everyone will be working virtually

-We plan to also give out official receipts as most of the business are the call centers in the philippines

My question sir is this:

-What are the essential steps in the business registration process?

-What are the things I can exclude since anyway I dont have an office--or is it mandatory to put a business address?

-Do I need to hire a part time accountant to handle the books and taxes we need to pay?

THanks so much sir, am fairly a newbie to this and your help is very much appreciated.