Here are a few ways to be involved in Citizen Science activities locally and on the national level:
Project Squirrel has information on squirrels, opportunities to share squirrel photos, and encourages us to observe and record squirrels in our neighborhoods.
Hoosier Riverwatch uses citizen scientist volunteers to monitor water quality. Loaner kits are available if needed. I've seen training available in September the last two years and have looked at the many critters monitored during different events.
Project Noah encourages us to document and share our nature findings. An interactive map can be used to find nature sitings in our area--we can add to this database and get help in identifying species.
There are several ways to be involved in bird counts through the Audubon Society. These involving documenting and sharing the birds found on specific days in specific areas. Local counts are set up for Christmas and other times of the year. Project FeederWatch is another option done from the comfort of one's own home. This runs November to April and involves a $15 fee.
The National Wildlife Federation also offers several suggestions for being involved in nature, such as FrogWatch, Monach Butterfly monitoring, star gazing, etc.
What do you do to be a citizen scientist? How could you be involved in the local or national level?