My recommendation would be to find some random "practice" niche.

Create a blog and do seo on long tail keywords.

Create a very cheap e-guide on a topic important to people in that niche.

Design the blog to sell your cheap product.

Connect the blog to an aweber (or any) auto responder.

Design the auto responder to sell your cheap product


Ofcourse at first you won't do that great, but you'll get two things which are INVALUABLE.... experience & momentum.

It doesn't matter if your first product sucks, because you're doing it in a niche you DONT want to go into for real. You might make some money, but you're going into things with the mindset of failing.

Anyway, after doing this. Improve on what you're doing (in your practice niche).... until you feel you're good enough to go into a bigger/better niche.

Some areas to improve:
Copywriting
SEO
Other traffic (ppc, etc)
Outsourcing (articles for blog especially)
Tracking & testing

Anyway, thats my two cents.
Hope it helps.