As for how to "get started," find something you're good at, find someone who has a related problem, offer to solve it for them at a discount because you are learning how to do this "solve problems for money" thing. Then, lather, rinse, raise your rate, repeat.
Also, for most of the 10 people I interviewed, I asked them for specific advice for people interested in starting to freelance. I hope it will help you!
There's also agencies that can help you, though this will typically get you into the role of a contractor, basically a hired temp, than of a consultant. But it's a common path to go from contractor for a client through an agency -> consultant for own clients.
For starters, things like: - Having a higher rate ($100+) gives perceived value. - Calling yourself a software consulting vs. developer I've found to be a big deal. - Being able to nail down the expertise you have (or want to have) and articulating it in a sentence. For example: I specialize in rapid development of web and mobile apps with the first iteration delivered within two weeks.