When fermenting a product, it is very important to make sure you have a food grade fermentation container that can be sealed and have adequate ventilation for the carbon dioxide gas that will build up when the yeast does its work. This ventilation can come, mainly, in the form of an airlock or a blowoff tube (a hose that goes from the top of your fermenter to a a container of water or sanitizer). The process of certain types of fermenting are going to depend on the style of alcohol that you are looking to produce.
An example of this would be making a lager style of beer. Lagers usually require the use a certain strain of yeast known as a lager yeast or Saccharomyces pastorianus. This yeast is going to be a bottom fermenting yeast, which means it ferments from the bottom of the vessel, as opposed to an ale yeast which is a top fermenting yeast. The lager yeast is also going to require colder temperatures than an ale yeast merely because that is how that specific strain is designed to be alive.
Making sure to adhere to the designated temperature ranges that are specific to the yeast you are using is very important. If you stray from the temperature range that is designated to a specific yeast may result in your fermentation stopping because the yeast is unable to stay alive and thrive.
A good way to track if your fermentation is thriving is to pay careful attention to your airlock. Fermentation, on average, should last between 7-14 days. Lagers are known to be slightly longer.