Get yourself a portfolio together. People will want to see what you're capable of.This can be anything, little jobs for friends, stuff you've developed for yourself, it doesn't matter as long as it looks good and works fine.
I am assuming that you don't want to do this full time. So you've got to be realistic about who to approach with news of your talents. You will not design for any big boys someday soon as you're not a professional (no rudeness intended, it's just the way it is ). Talk to your local school, library, church if you're so inclined. Neighbourhood watch, your sister's wedding site. Charge little, work fast and always deliver more than you promised. On the matter of charging, keep an eye on your time. Find an hourly rate that you and your clients are both happy with, then stick with it.
Have fun.