It is definitely possible to make more than $100k a year as a writer, but the money doesn't come from wordrates alone. You have to sell articles into books and do occasional speaking gigs. Check this book out: http://www.amazon.com/Quick-Dirty-Guide-Freelance-Writing-ebook/dp/B00NT7A6HI/ref=asap_bc?ie=UTF8
You don't break into long form. You start writing it by selling a kick-ass idea to a real editor at a real publication that pays real money. This might help: http://www.amazon.com/Quick-Dirty-Guide-Freelance-Writing-ebook/dp/B00NT7A6HI/ref=asap_bc?ie=UTF8
I published a bunch of my successful pitches here: https://www.amazon.com/dp/B00NT7A6HI
I got started just writing for magazines. I just do books now. It's possible, but the model is pretty brutal. Here's something I wrote about the process. https://www.amazon.com/dp/B00NT7A6HI
Seems appropriate to post this here: https://www.amazon.com/dp/B00NT7A6HI
I wrote a guide about freelancing a while back where I go over a lot of stuff about this. It might be useful: https://www.amazon.com/Quick-Dirty-Guide-Freelance-Writing-ebook/dp/B00NT7A6HI/ref=asap_bc?ie=UTF8
I'm also working on a more up-up-to-date video series, but haven't released it yet.
In essence though, yes, a website helps secure clients and gives readers more information about you. I rarely sell anything directly from it.
I give a lot of advice to new writers on my blog which you can find if you snoop around on my website scottcarney.com Or, you can take a gander ay my ebook on freelance writing which is $3 on amazon or free if you sign up for my mailing list.