
Here are some helpful paint calculators from various manufacturers and retailers for estimating the amount of paint needed for covering walls, ceilings, or exteriors. Compare a few and you should have a rough estimate of what you'll need.
PPG Architectural Coatings
Benjamin Moore
Pratt and Lambert
Glidden
Paint Quality Institute
Improvnet
TrueValue
Domino Magazine
Metric
Bunnings Warehouse
Dulux
BBC

There are some axioms related to home improvement that are just plain false but have been perpetuated by real estate agents, contractors, or homeowners who want to believe in some hard rules when it comes remodeling or renovating their home.
Here are some home improvement myth busters.
Top 4 Home Improvement Myths [HGTV]
Dean Johnson Debunks Some Common Myths About Home Improvement [Hometime]
5 Homeownership Tax Myths [MSN]
Debunking the Myths of Bathroom Design [Doityourself.com]
Five Mold Myths And Facts For Homeowners [Home Improvement Time]

Here are some great suggestions for planning a child safe garden that maximizes outdoor fun but protects both your children and your foliage.