Where can I find some general guidelines for welding ventilation? What types of ventilation can be used to remove air contaminants from a welder's breathing zone? What are some examples of Local Exhaust Ventilation? The Canadian Centre for Occupational Health and Safety answers these questions and more on their website:

http://www.ccohs.ca/oshanswers/safety_haz/welding/ventilation.html

What are some tips for a good working posture while welding? What is an example of a standing workbench design? What is an example of a seated workbench design? The Canadian Centre for Occupational Health and Safety answers these questions and more on their website: 

http://www.ccohs.ca/oshanswers/safety_haz/welding/ergonomics.html