Techniques and basics

Lettering
http://www.graffitistudio.net/ultimate-guide-draw-beautiful-graffiti-letters

Six steps to becoming an artist
http://www.graffitistudio.net/steps-become-graffiti-artist

10 steps to making a stencil
http://www.wikihow.com/Make-a-Graffiti-Stencil

Tutorials good!! Everything you might wanna know!
http://www.stencilrevolution.com/tutorials/

how to draw different styles
http://www.dragoart.com/graffiti-c381-1.htm

Creating a Tag
http://graffitidiplomacy.com/CreateYourOwnTag.html

Tipos and exercises to improve your spraying (good)
http://abduzeedo.com/tips-and-exercises-master-spray-paint-0

Graffiti artists

Graffiti and street artists
http://www.graffitistudio.net/graffiti-artists

50 of New Yorks best writers
http://www.graffitistudio.net/graffiti-artists

50 amazing works
http://www.graffitistudio.net/graffiti-artists

Graffiti movies

Graffiti documentaries
http://graffitimovies.weebly.com

Top five graffiti movies (worth finding)
http://timelapselove.hubpages.com/hub/top-5-graffiti-movies

Getting up youtube link
https://www.youtube.com/watch?v=Q7xBo-6XD-s

Infamy youtube link
https://www.youtube.com/watch?v=mcUMl5ohKN4

Alter Ego
https://www.youtube.com/watch?v=SLA8BQtffNw

Styles of graffiti

Good examples of styles 

http://www.fatcap.com/graffiti-styles.html

Arts or vandalism 

http://www.obsidian.bild-art.de/index.php?option=com_content&view=article&id=238%3Agraffiti-art-or-vandalism&catid=70&Itemid=79&limitstart=1

Different forms and techniques of street art

http://www.graffitistudio.net/different-forms-street-art

History of Graffiti flow chart

History of Graffiti Links and references

Graf Archeology (cool site)
http://grafarc.org/flash/view.htm

History and definitions slide show
next_slideshow=1http://www.slideshare.net/thennif/graffiti-4553402?next_slideshow=1

Influential street art
http://www.slideshare.net/ilaeadigital/street-art-15119960?related=1

Major moments in history
http://decorateatx.tumblr.com/post/22115600337/timeline-history-of-graffiti

Good description of origin
http://nychicagograffitihistory.weebly.com/graffiti-history-timeline.html

The hip hop era
http://www.hiphoparea.com/graffiti/graffiti-styles-style-timeline.html

Culture graffiti and politics
http://www.graffiti.org/faq/werwath/werwath.html

Banksy Robbo War
http://twistedsifter.com/2012/01/banksy-vs-robbo-war-in-pictures/