You should also get yourself some paper overalls (they are cheap) and wear latex gloves as the paint can be absorbed through skin.
To add to Steve's post about breathing through the 3M masks, if you can SMELL ANY paint fumes then the mask is used up.
Also check that its the 06941 mask, as others look the same but are different filters.
An air fed mask is not that expensive either, though you will need a big compressor to feed it!
Re the latex gloves, I'd recommend NITRILE gloves instead, (powder free) as latex is a known allergenic and is very good for causing dermatitis or exzema on your hands after use (depending on person it can be days or years).
Thanks guys being out of work at the moment £10 is a lot so to lend off steve has helped me know end and prolonged my life (my wife hates you steve) :D