After about 14 years of daily reading of DVC boards, I think the blow-up-in-your-face incidents are VERY rare. The vast, great, majority of members who rent are just Disney vacationers like you or me, who can't take a trip that year and are renting out their points to try to cover their maintenance fees and/or loan payments.
A couple things to keep in mind if you decide to rent:
1. While the true scammers are very rare, things do go off the rails occasionally, because either the owner or renter isn't communicating well, and/or the terms aren't clear, and/or one or both parties don't understand DVC's rules. To me, this is an argument for using a broker like dvcbyrequest.com, who are extremely experienced in the ins and outs of DVC and renting, and who provide both parties with a detailed rental agreement that spells out who's responsible for what, the payment terms, etc. Especially for a first time renter like yourself, I think that's worth any additional cost that comes with using a broker.
2. To me, the biggest 'gotcha' is that you need to assume that your reservation is FINAL. No changes, no cancellations, no refunds. Because of tight availability at DVC resorts, it's usually not possible to make changes in reservation dates, or to change resorts. If there's a chance you may need to cancel because of family or work commitments, or because of illness, either get trip insurance or don't rent. You won't be getting your money back, otherwise.