Some principles on Arraiolos: 
(1) Everything ´happens´ on the right side. The wrong (or the reverse) side is ´perfect´ as all beginning and ending of a thread in the embroidery is hidden on right side under the stitches already done. 
(2) A single stitch has always 3 overlappings of the thread on it. Sometimes 4. 
(3) A ´filling´row is always from a different direction as its previous and the one following.
(4) Rows are always worked across the longest side of the rug. If you working a square cushion, for example, choose the botton of the motif to work horizontally from it. (See picture of Pag.5 below as they speak of "sentido do bordado").

Revista Clássicos de Arraiolos Edição 103 - Março 2009
Editorial Nascimento - Tuttirev Portugal

This is the continuation on "Curso de Arraiolos - 4a Parte".
This is the best explanation on Ponto de Arraiolos I have found.
That´s why I´d like to share it here.

Suggested sites where magazines "Clássicos de Arraiolos" can be bought from:

http://www.lindentea.eu/

http://www.alusitana.com.pt/

 Sometimes I find old copies from www.olx.pt in which I usually negociate with the seller.

 Revista Clássicos de Arraiolos Edição 102 - Janeiro 2009

Editorial Nascimento - Tuttirev Portugal

Only pages  "CURSO DE PONTO EM ARRAIOLOS" are shown since my purpose here is to share how it is done.

Hint: Not everybody does Arraiolos the same way. Check the Youtube video "Curso Básico de Arraiolo" (https://www.youtube.com/watch?v=sMR1SsGttuU) from Ana Silveira. Each row she does the stitches always the same directon.

I will comment on her video in the future.

 

 

Revista Clássicos de Arraiolos Edição 101 - Novembro 2008 - Editorial Nascimento - Tuttirev Portugal

Nice lesson on how to start an arraiolos rug. 

Just the pages with "Curso de Arraiolos - 2a Parte".

They use the design "Azul e Rosa II" that was published previously in the "Clássicos de Arraiolos" issue 23.