Hi, there are lots of articles and "how to's" around and I suggest you have a look.
I tend to use a separate account for the agents (different from the service and agent account) and this account will have specific permissions such as dbowner on the subscriber only, access to the file system that contains the replication files i.e. snapshot.
You could go mad and have a separate account for each agent which is not a bad thing, it just adds a little extra complexity.
Your setup sounds like a pretty straightforward arrangement.
Graeme