I have a supposed opportunity to get in with an individual with advertising and a side business of his, renting IP addresses. He has asked me to set a dedicated DSL account at my house. Is there any risk for me? I have other devices on a separate DSL account and modem. I'm a novice at networking and not too advanced on computers, just wondering what my risks are, if any, of him taking advantage of me, due to the amount of scammers and hackers?
Yes, there is significant risk to you. The value of allowing someone else to "rent" access to a DSL connection at your house is so that they can pretend to be you in their online behavior. If it's your name and address on the agreement with the ISP, then typically you're the one responsible for what happens on that connection. Actual legal liability varies by locality, but your exposure it typically pretty significant.
There have been several instances all over the world (Austria, Germany, USA, and others) where individuals have been arrested and charged because of illegal traffic (usually child porn) going through their Internet connection (typically TOR exit nodes).
Whatever this individual is planning, there's a decent chance that it will end up with you in jail.
Ask yourself this question:
Why is this individual asking YOU to set this up, at your house, under your name, instead of doing it himself, under his own name, at his own property?
Don't like what just came to mind? Good, you shouldn't.
The basic scam predates the internet, and what is going on is that this individual is essentially using your identity, person and property as a mule. Think drug smuggling if you'd like to draw a more direct analogy, but bear in mind, if this person engages in illicit activity, it's YOUR door the police will be breaking down.
YOUR name is on the contract, the line is at YOUR house, and YOU agreed to let this person do... whatever they were going to do. Frankly I cannot imagine any compensation they'd be willing to pay (Millions of $ would be insufficient) would compensate you for the risk they pose to you.
Cut your ties to this person immediately and count yourself lucky to have sought informed advice.