The first 2 steps are correct, however, you want to make sure you have done
your due diligence and proper research to ensure what you're offering is some
thing that is in high enough demand.
Once you've done your research and you are certain you want to proceed, then
it is time to register a domain name. I would suggest something that is either
directly relative to what you're offering, OR something that is so general in nature,
in case you ever decide to change the "subject matter" of that site's content.
Once you've registered the domain, you can then post your squeeze page,
with your opt-in form, however, I would never direct them directly to a sales
page, not when/if you're just starting out.
You want to first build a relationship with your subscribers. Show them that
your overall and initial intent is to really HELP them, NOT make money off of
them. Most people are smart enough to know that if they're added to your
mailing list, they'll eventually receive pitches for other products.
Schmooze your subscribers first. Gain their trust by giving them helpful and
useful information about the subject at hand. In today's world, information
of all sorts is readily available on ANY topic. Find some relative information,
reword it and send it to your subscribers.
Once you have gained their trust, then it is time to start selling, slowly
of course, and only relative and trust worthy offers should be promoted.
There's no easier way to ruin your good name than to gain someone's trust
only to lose it immediately by promoting garbage.
Building a relationship with your readers FIRST is just a suggestion, however,
it is ultimately your decision as to how quickly you want things to go and how
exactly you want to do things.