I’ve recently starting listening to a great podcast on soundcloud called “Ask Pat” and it’s full of good ideas about running business and/or website. He’s got a lot of great advice that applies to a range of fields and even though he’s not Jewish he focuses a lot on how to make money while still developing your family life so it’s not all just about chasing another dollar.
In general I’d recommend something you find interesting or enjoy doing already and consuming as many books/blogs/podcasts/etc. as you can about it to really get a feel for the field.
A BIG thing I’d recommend is look up people involved in that line of work. Find a business or person doing something you’re interested in and find their email address off their website or their number in the phonebook.
If they are located near you then visit the office in person. Basically say you’re interested in pursuing a career in that field and you’d like to know what their day-to-day work entails as well as what kind of education or experience they needed to get into it as well as other advice they have to offer. Also ask how much you can expect to earn doing such work.
Don’t be shy – people generally like talking about themselves and will be flattered that somebody values their opinion or experience. Maybe they will be busy when you get a hold of them but will be willing to speak in the evening, etc. so don’t be afraid to chase them. The worst they can say is no or ignore you.
Best advice for last…. DAVEN like crazy for clarity!!! And stay positive – often failures are just Hashem’s way of testing your resolve.