Understanding (and Avoiding) Software Patents?

An anonymous reader asks: "I'd like to write some Free backup software, but this area is mined with patents. I downloaded one and tried to understand it, but the 'claims' section (arguably the most important part) is made up of utterly incomprehensible patentese, and I can't afford to hire a patent attorney to help me understand it. Are there any free or cheap ways to learn enough about patents to understand them, so I can figure out exactly what is patented and therefore avoid it?" "How different does my software have to be in order to be non-infringing? The patent I tried to understand is Dantz's 5,150,473. Many, including Slashdot readers, have said what this patent covers, but from reading the patent itself, I would never have guessed. Also, there are lots of other patents to understand and avoid, so I'm looking for general information on how I can unravel it all into language I can understand."