I assume you have installed the vCenter adapter? Configuration of the adapter (including connecting to vCenter) can be found in the tech notes included with the adapter.
Just out of curiosity, why did you decide to go with standalone? You will be giving up the capacity reporting and analysis by going with the standalone install. Also, it's a lot easier to get working with your vCenter as registration is handled via the Admin UI and includes answering a few simple questions.
Unless you have a particular reason to go with standalone, I'd recommend you just download and deploy the vApp.
Visit my blog for vCloud Management tips and tricks - http://www.storagegumbo.com