COLUMBUS — Facebook and the Columbus Chamber will host a seminar at 10 a.m. Friday at COSI, 333 W. Broad St., meant to teach local small-business owners how to optimize their presence and engage customers on Facebook.The seminar is free, and all businesses are welcome to attend. Sen. Sherrod Brown will kick off the seminar with opening remarks. That will be followed by a presentation from a Facebook small-business expert on the latest Facebook best practices and strategies. There also will be a question-and-answer session, featuring a panel of local small businesses that will share their Facebook tips, tricks and suggestions. To register and for more information, go to fbcolumbus.splashthat.com.