first time parents: taxes!

I know it's not really close to tax season yet but what should I know about taxes and my daughter? my fiance and I are yet to be married (despite me always referring to him as my husband or jokingly future ex husband) and aren't sure whether it would make taxes next year easier or more difficult with a new dependent. Do we need to notify our employers if we're considering filling jointly? why is something mandatory not taught in schools and be less confusing in general?