Hi and welcome to Just Answer!
We are going to file the 990 post card since we grossed less than $25,000 for 2011. Is this correct or should we be doing something else as well?Everything you are doing is correct - even the determination letter was not issued yet - you are still 503c3 organization as long as the letter will be issued.
The problem will be only if your application will be rejected.We paid our state license and city licenses for Alexandria, Virginia. This is where our business is located. Do we have to file Virginia Taxes?
Your non profit organization should be registered in Virginia - see more information here - http://www.tax.virginia.gov/site.cfm?alias=NPOFAQs
But you will need to provide the determination letter from the IRS
See here - http://www.tax.virginia.gov/taxforms/Business/Registration/R-1.pdf