We make blessings over every type of food or drink we consume, but grape juice and wine have a special status. This is especially the case  when we make kiddush on Shabbat. For an explanation of the Friday night kiddush: http://www.aish.com/sh/ht/fn/48967396.html and an additional explanation of Shabbat day kiddush: http://www.aish.com/sh/ht/sd/48970761.html

Friday night, just as the sun is about to set and Shabbat has nearly arrived, the woman of the family lights Shabbat candles. The candles don’t just add additional light; they also bring more peace & tranquility into your home. For an explanation of the procedure and meaning of lighting Shabbat candles: http://www.aish.com/sh/ht/fn/48965051.html and http://www.aish.com/sh/t/cl/48972066.html. 

There is a blessing that we say before partaking of drinks (except for wine/grape juice), meat, fish, dairy products, and candy. This more general blessing encompasses many foods by definition, as it means "through Whose word everything came to be". This blessing unlike the blessing for kiddush and candle lighting, can be said nearly anytime -- not only right before or on Shabbat. 

For more on blessings: http://www.aish.com/jl/m/pb/48951311.htm and http://www.aish.com/48952001.html.