I guess it depends on what kind of copywriting your'e talking about. The definition has expanded to mean SEO copy in the past few years. Really mastering the SEO takes study, plus some trial and error. Learning to do direct response style - which is the foundation for all sales copywriting - isn't too tough. The best sources for learn how it's done are Dan Ogilvy's "Ogilvy on Advertising," and the info. at www.thegaryhalbertletter.com - That's the basic stuff. Your real problem is going to be getting clients. These forums are not the best place, let me tell you.
Experience, hard work, patience, trial and error. My copywriting skills are still not where they need to be. Focusing your research, learning how to be succinct, and effectively using your time are huge priorities for me.
One of the best ways to learn copywriting is to COPY BY HAND good "copy" (copy= sales letter") material. Look for famous sale letters or find something you think is hypnotic enough and just sit down and write it yourself. You wont believe how much you could learn from that....
Start practicing it. Create a blog... put ads on it.. and start writing... LOTS. Don't give up and practice. That is the secret, IMO.
There are lots of Writers Forums. I suggest you start a blog on a free blogging platform. You will learn while doing it.
Two great books to learn from is "The Copywriter's Handbook" by Bob Bly and "Ca$hvertising" by Drew Eric Whitman. Both are packed full of useful information and examples that are easy to understand.
“The Queen’s English And How To Use It†by ©Bernard C. Lamb (ISBN 978-1-84317-482-0), published by Michael O’Mara Books Limited, 2010. What is good English, and why do we need it? The Queen’s English shows how language, used properly, has enormous power to inform and inspire. Used incorrectly, however, it has the same power to baffle and bemuse. This book wears its learning lightly, reminding readers how to use the basics of grammar, punctuation and spelling. It also teaches them new tips and tricks of style, vocabulary and the use of foreign phrases, to give their writing and speech an impressive flair. Using hilarious (if unintentionally so) examples from people who really ought to know better, it shows where bad English leads us astray, especially in terms of meaning, precision and clarity. Authoritative but accessible, here is a book for anyone who has any feeling whatsoever for clear, stylish and accurate communication.