As Jarett noted, there are many different interpretations of the term Business Architect and different understandings of what that role involves across organizations. However, there are a number of professional organizations and assocations that are trying to put some standardization and discipline on this role.
Here is a good article from the BA Institute that gives an overview of the Business Architecture role and value to an organization:
http://www.bainstitute.org/resources/articles/defining-term-business-architecture
The Open Group (OMG) has lots of resources on business architecture and enterprise architecture - membership is free to access webinars, white papers and other material at www.opengroup.org.
There is also a Business Architecture Guild that is building a guide to Business Architecture knowledge ("BIZBOK", similar to the BABOK and PMBOK). Their website also has a number of online references (not sure which ones are available free, but you can browse through and check them out):
http://www.businessarchitectureguild.org/More_Resources
As a Business Architect, I tend to use diagrams like value-stream maps (see first linked article above) and strategy maps; and I conduct capability analyses, stakeholder impact assessments, business cases, SWOT assessments, etc.
These may or may not be what your organization needs or wants from you in this role - as Jarett also suggested, there are some key questions that you can ask your supervisor and executive management teams to determine the best way for you to bring value in this new role.
Happy to chat further offline as well - you can connect with me on LinkedIn if you like.
Sandy