The “Tea Party Army” seems to be a fine example of an organization to NOT send donations. While many new organizations may be worthy, there is no doubt that people are trying to capitalize on grassroots fervor for their own personal gain.
See this article about “Tea Party Army” on Open Secrets and use them as an example of when to steer clear.
It might be easier to conduct your due diligence on local organizations, and local organizations may have a more direct impact upon the quality of life in your community. Look at your county level first, and if there is nothing worthwhile there, then consider something at your state level. For example, in Clark County, WA, the Clark County Republican Party has recently demonstrated good activism to support or defeat issues and candidates which directly impact our way of life. Their “Core Principles” mechanism demonstrates both innovation and substance. At the state level, the Freedom Foundation has a good track record of both political and legal actions which make a difference.
I encourage you to support political activism with your donation dollars, but do so with a prejudice toward your local community first, and view these emotionally charged appeals from national organizations with a healthy degree of skepticism regardless of how good their rhetoric may sound.
If you believe in bottom up politics and leadership, work toward changing your neighborhood and your county first.