Well it depends where you want to be, design isn't a well paid profession despite what people think. Just like in any industry there are varying levels of professionalism. Many people set themselves up as designers and do 50 quid logos, flyers and business cards, because they like tooling around in applications, people do make a living this way.
If you want to work for a top agency, you're going to need experience, and most likely a degree, design is a craft and there's a reason why people spend years studying it.
If you're dedicated enough you can self-teach, people have done this, but I wouldn't recommend it. Also you rarely get designers who specialise in websites, infographics and brand/identity, because they're such specialised fields in themselves.
It could be a useful exercise for you to call up local agencies, or design businesses that you'd like to work in that specialise in what you're interested in, and ask them what they expect to see from potential employees - qualification and portfolio wise - try and get a work placement somewhere, you will learn lots this way. Then you can set about planning how you're going to get there. Fundamentally if you want to make a career out of it, you need to love it, knowing applications isn't enough.
Anyway, for starters you should be aware of what's going on in design, here's a list of some sites that should help you with that;
www.formfiftyfive.com
www.crblog.com
www.dropular.net
www.typeneu.com
www.reformrevolution.com
Some top agencies;
www.pentagram.com
http://www.wolffolins.com/
http://marquecreative.com/
http://www.seadesign.co.uk/