When in the season does the MLB start televising games?

Opening Day, and they televise some of the Spring Training games. But for the season it's Opening Day.

The only games "the MLB" televises are on the MLB Network and they start shortly after the beginning of Spring Training: around the first or second week of March.

MLB games are televised by local/regional affiliates such as Fox Sports Net and Comcast, regional networks like NESN and MASN, as well some national games on ESPN and Fox Network. San Diego has Channel 4 (Cox) and the Braves, Yankees, and Mets have their own networks.

Local/Regional affiliates usually show some spring training games as does ESPN. YES shows a lot of Spring Training games.

MLB Extra Innings Package commences on Opening Day. Fox Network starts their Saturday broadcasts a bit after the start of the season.

April 4, 2010 - October 3, 2010

...televising by whom?

local TV--- spring training
national TV -- opening day

Opening Day.

Bob