Just simply put the plants ( 2 or 3 ) in a corner of a room under a 400w hps.
Is really necessary a ventilation system for 2 plants?
I want to buy some fans like this <<
http://remodelista.com/img/sub/freudtablefan.jpg >>
My plants will grow?
It takes a little more than air and light to grow a plant, but yes, in theory, a 400w light, in an open room, with some fans for air movement would be sufficient.
However, when you get into flowering you will probably need an air extraction and filtration method to reduce the smell. Additionally, cannabis likes fresh air, and it's nice to have an exhaust fan and a carbon filter to keep clean, fresh air in your bud room.
Is this an absolute necessity, though? No. You can grow this plant under CFLs with a single fan on it and will do fine.
You might want to run a search on Subcool's LAWS--Light, air, water, and soil. It will tell you most of what you need to know about the basics of growing. You can also watch all of Jorge Cervante's videos on youtube. Very clear, step by step stuff.
Happy growing to you!
