Adding new article to existing publication

I have my databases running on SQL Server 2005.I have Transactional replication setup between 2 databases - source being my transaction db and the target being the reporting database.I am going to add a new article to the existing publication, and my question over here is when I add the the new article do I have to generate a new snapshot and then reintialize the subscription.And also when I am generating the new snapshot will I be able to access both the source and the target databases.Thank you all in advance.