Hi, thanks for your help. I have lots of weeds and crab grass and am getting ready to apply crab grass prevention. Additionally I have brown spots throughout my yard, almost looks like dead grass. Photos attached Thanks for your advice.
Based on your photos this looks like nimblewill, a perennial warm season grass. It thrives in shade in infertile soil but will move into sunnier areas.
See our page on management http://extension.umd.edu/hgic/topics/nimblewill