Here is consumer-oriented information from the EnergyStar site:

http://www.energystar.gov/index.cfm?c=products.pr_tax_credits

DOE's Recovery and Reinvestment Act site covers Recovery Act funding in states and municipalities:

http://www.energy.gov/recovery/index.htm

Here's EERE's Recovery Act site:

http://www1.eere.energy.gov/recovery/

Going to buy a hybrid? Check the IRS site on vehicle tax incentives:

http://www.irs.gov/businesses/corporations/article/0,,id=203122,00.html

The IRS site on alternative vehicles is also good for this:

http://www.irs.gov/businesses/corporations/article/0,,id=202341,00.html

There's also a database of state and muni spiffs for renewables and efficiency efforts:

http://www.dsireusa.org/

Finally, the Recovery.gov site outlines federal funding:

http://www.recovery.gov/