Porn is a business. Understanding a business is usually a key factor in improving your chances at long term success.
Given the costs associated with "running your own shop", even just technically, it's not a bad idea to sign up with a cam site or otherwise gig with an existing photographer/studio at first.
That will get you "in the mud" of the day-to-day (though usually much more irregularly-scheduled) work at virtually no cost. If you like what you find, and think it's a good long term (or even medium term) choice for you, then you can work to build connections with industry contacts, and get great advice that will be specific to your situation (gender, orientation, body type, local porn production market, etc).
I would only advise starting out 100% solo if you have a deep-down knowledge that it's for you, one or more people willing to work with you in front of and/or behind the camera, AND the technical chops to put together your own site and fix it when it breaks.
If you have all of those, plus an unshakable desire to succeed, you can test the waters for as little as $2-5000 in home studio equipment, and then hire out all the accounting/legal assistance you'll need for a similar amount. All told, if you build up a paid following in the mid-hundreds, you may break even your first year.
It's a lot like trying to go pro with blogging – a lot is going to depend on your quality and consistency until you are well established… And like blogging, ultimately the "real money" will probably come from somewhere else – a pro-porn gig, speaking/appearance fees, strip club work, book deal, etc.
I don't normally like to link out to NSFW sites, but I recall meeting someone very much in the "amateur porn" vein a few years back, just a straight-up hustler trying to get rich via the adult industry. He's pretty open about his experiences good and bad, and his site might be a good read to encourage/dissuade folks interested in jumping into the biz:
http://www.shimmysbookmarks.com/ (NSFW, again, for the record)
Upon further thought, you can get a real good general "feel" for the business across the various amateur/pro tiers by making a twitter list of the performers you find online (professional porn is big on twitter)… While the ones mentioned below are all pros, they give some decent insights into less glamorous aspects of the business now and then, including the recent Cal-OSHA meeting[*], stressing about running late for shoots that get cancelled, relationship issues, and the mundane stuff like finding pet sitters for those award shows in Vegas:
@wolfhudsonxxx
@danadearmond
@giadimarco
@thejessicadrake
etc…
You might also try running searches for people/lists of stars at listorius.com. Again, a good way to get a more direct "pulse" for the industry and its issues.
deano.com 