Creating Several Accounts

[John Bunker]

Hello,
I am wondering the best way to start using GNuCash.

I have two different business accounts. 


One is a service type account (invoicing for services rendered).
               I pay myself out of this account


The other is a non profit account that i use to keep track of donations made 
               I pay myself out of this account as well, but also must keep track of and make payments for housing allowances, and other things as well

So then i have a personal account that I use for all of my personal transactions

Can i use one file for all of these, or do i need to use separate files?

Any guidance would be appreciated
John