LINCS https://community.lincs.ed.gov/ An excellent resource for connecting with other Adult Education folks across the country and finding tons of resources.
PHET https://phet.colorado.edu/ Online simulations of math and science concepts. These are very useful, engaging and fun. The HTML5 ones work the best.
Illuminations http://illuminations.nctm.org/Default.aspx These are lessons, games, activities from the National Council of Teachers of Mathematics (NCTM)
TEAL https://teal.ed.gov/sites/default/files/Teal_Math_Works_Guide_508.pdf Math works guide from TEAL (Teaching Excellence in Adult Education).