Soil testing

Ok, so I feel like I'm starting to grow enough as a gardener to start paying better attention to the soil. I've started learning about compost and soil conditions, and have read a great book on it called Teaming With Microbes. I think I would like to try testing my soil, but I don't want to waste money. Do any of you test your soil with tester kits? Electronic testers? Think it's not worth it? Thanks. =)

I have used tester kits for NPK and ph. It isn't too difficult, but didn't really tell me much that I didn't know from common sense and reading about typical soils in the Northwest. Acidic, with low phosphorus. It was kind of fun to do with my kid as a little science experiment. I have shied away from the electronic ones as rather expensive. I sent away soil samples to a laboratory when to check for heavy metals (arsenic and lead) when I learned that could be a potential problem in my neighborhood. It cost $40 to do it, but I wanted to know if I had contaminated soil. It was a relief to know there was no problem with lead. The arsenic was a little high (due to windfall from the copper smelter in Ruston) but much much lower than some nearby locations that seemed to have caught most of it. It was recommended that we add lots of organic material to the soil, which is what I was doing anyway.