Unless you know you will be serving many requests per second, or have very data and/or CPU-heavy business logic, then you should be perfectly fine starting out by deploying both tiers on the same application server. Starting out by deploying to a single Glassfish application server using local interfaces lets you skip a lot of complexity in the runtime environment.
This in turn will allow you to use the simplest form of @EJB-injection in the web tier to access the session facades in the business tier. Local intefaces are faster because the application server can pass references rather than RMI proxies between the tiers and it lets you skip the JNDI lookups. You can always change the annotation later on, or introduce remote interfaces if you later find other reasons to deploy the tiers on separate servers.
Glassfish supports clustering, so you might never have to explicitly separate the two tiers--it all depends on the actual usage patterns, so performance monitoring is key.
Deploying the web tier as a WAR and the business logic as an EJB jar is the right thing to do. Depending on the size and the logical structure of your application, you might want to break that down into to multiple modules.
Maven takes care of building the archives. Make sure you define a sub-project for each war and jar archive, plus a sub-project for assembling the EAR-file. The latter project will pull in the war and jar files produced by the other sub-projects. String all the projects together with a master maven project and voila, you have the flexibility to build each component separately, build the entire thing, or any combination in-between.
