What is the best way for me to test the water in my home for lead?

Get a home testing kit that includes water and not just paint chips. Follow the directions carefully. You can also call an environmental laboratory, and they will supply the glassware and give you instructions, but it will be more expensive.

if you google "lead test kits" you'll get a million results of different companies that will sell you a test. Alternately, you can get your doctor to do a blood test for lead, which is a good way of seeing if you've been overexposed through other sources, such as paint chips in your house, etc. If you are worried about your "body burden" of toxics I would also recommend getting tested for mercury (which you get mostly through eating fish, not through water in your house). You can snip a piece of your hair and get it tested for mercury by buying a kit at a non-profit rate at http://www.sierraclub.org/mercury

You should be able to look at a water quality report from your municipal water company, unless your on a well.