Passing a RaiseNow one-off donation (transaction) to Salesforce will address the following objects in Salesforce:
Creating a contact will cause Salesforce/NPSP to automatically create an account object of the type household within Salesforce. The contact will have an opportunity linked to it. The opportunity StageName will automatically be set to "Closed Won". If the RaiseNow transaction specified a Salesforce campaign this CampaignId will be referenced in the created opportunity. Please note that an invalid Salesforce CampaignId will be ignored and it simply won't link any campaign in the opportunity.
Example of a contact:
Example of an opportunity
Example of a npe01__OppPayment__c
Example of a RaiseNow__Transaction__c