Ok, first let's clarify a few things. Oftentimes, the term "node" can get misconstrued depending on how your environment is configured. Perhaps I should have been more clear in my explanation of adding nodes to a profile. Our environment is almost completely virtual (ESX) so in our world each virtual "server" we create is the "node". Once the "node" has been created, WAS is installed as part of an image (along with MQ, WSRR, and a host of other IBM products we currently use). After the image has been installed on the "node" we then add the "node" to its respective cell and complete the cell based configuration (including creating dynamic clusters, which in turn creates the servers - they may be application servers and/or ODR servers depending on what we created the new "node" for).
I think what Stan and Paul are referring to are what we call "servers", and how to create/configure them depends on whether or not your environment is standalone or clustered, and also depends on if you're using Virtual Enterprise.
After reviewing your initial post again it looks like you have a standalone WAS 7 "node". So my questions to you are: are you interested in creating another "node" so you can cluster it with the existing "node" for high avaliability? Or are you interested in creating additional application "servers" on the existing standalone "node" (i.e. server1, server2; etc)?
Hopefully this clears the mud a little :-)
Danielle