What about a super simple "sideline" site?

Most people are not going to buy the first time they see your offer. Spending money on advertising isn't a bad idea, but you could certainly help leverage your costs by getting subscribers.

One place I've bought from a number of times asks you to sign-up to receive the first two or three chapters free. This seems to work well.

If you do a search for "free autoresponders" you find plenty of services -- I can't vouch for how good any of them might be, but it would give you a place to start.

For hosting, try hostgator.com. They have over 4,000 free templates and some sort of free website builder you get with your account.

Summary:

The basics include a website that will attract subscribers, and built in a way so it doesn't scare people away. You should have a domain name, a hosting account and a plan for getting your offer in front of your target market.

Best Regards,
Steve MacLellan