Presente Simple - Presente Continuo

The Present Simple is used for:

Se Utiliza el PRESENTE SIMPLE cuando se expresa una accion real, rutina, o habito.

• regular actions or events 
  He plays tennis most weekends.
  
• facts 
  The sun rises in the east.
• facts known about the future 
  We leave at 8.30 next Monday 
  
• thoughts and feelings about the time of speaking
  I don't feel very well.

The Present Continuous is used for: 

Se Utiliza el PRESENTE CONTINUOS para describir el futuro expresando en el tiempo presente cuando se refiere a un acontecimiento previamente planificado.

 Formula: Subject + Verb to be + Verb + ing+ Complement

• What are you doing today? (Que vas a (piensas) hacer hoy) 

• In this mornig, I'm cleaning the house and then I'm meeting Mariana for lunch.( Por la mañana voy a limpiar la casa y luego voy a encontrarme con mariana para almorzar)

• the time of speaking ('now')

• Shh, I'm trying to hear what they are saying .
• things which are true at the moment but not always
  We're looking for a new flat.
  
• present plans for the future
  We're having dinner with them next week .

NOTA IMPORTANTE: I'm cleaning se traduce "Estoy limpiando", sin embargo cuando la oración expresa futuro se traduce "Voy a limpiar", es decir el presente continuo puede tener dos traducciones.

Look at these examples :

• I don't usually have cereals for breakfast but I'm having some this morning because there is nothing else.
• I often cycle to work but I'm taking the car this morning because it's raining very hard.
• I'm thinking about having my hair cut short but I don't think my husband will be very happy about it.
• My parents live in Washington but I'm just visiting.

Note how, in all these examples, we use the present continuous to talk about events which are temporary/limited in time and the present simple to talk about events which are habits/permanent.