Tamper. First on the list is a coffee tamper. 
Knock Box or Bin. This is a dedicated bin to knock your used coffee into. 
Milk Jug or Pitcher. Can't make a flattie without a pitcher to steam the milk in. 
Thermometer
Scales
Shot Glass. 
Cleaning Brush and Cloth.

Barista is the Italian word for “bartender." In Italy, baristas serve drinks of all kinds, not just coffee. In the United States, however, the term “barista" is generally only used for those who serve specialty coffee drinks. Most specialty coffee shops serve coffee drinks based on espresso.

A tamper mat is a must for any espresso coffee environment and are used to balance the portafilter while tamping the ground espresso coffee and an ideal place to house the espresso coffee tamper. A corner coffee taper mat is fixed in place up against the corner of the table and wont move when tamping.

Release your coffee passion.
Study the history of coffee.
Don't be afraid of the espresso machine.
Learn how to steam milk like the pro's.
Learn the hot drinks recipe.
Give excellent customer service.
Don't cry over spilt milk. Slip-resistant work shoes for baristas.

Although the term barista technically refers to someone who has been professionally trained in preparing espresso, it may also be used to describe anyone with a high level of skill in making espresso shots and espresso drinks, such as lattes and cappuccinos.

Portafilter. The handle that the filter basket sits in. Usually has a single or double spout, to allow the espresso to fall nicely into the cup.

More often than not, a good personal coffee machine is well worth the cost. You'll not only be saving more money per cup as opposed to buying at a coffee shop, but it's also faster and more convenient than going out to your local coffee place.