Prepare yourself for the fact that your business will take a year or longer before you start to make any money. Finding and keeping customers is a venture in itself. Often we make the mistake of putting all of our energy into finding new customers and not keeping up a relationship with the clients we already have. Finding that first customer is not easy. Be sure you tell everyone you know that you've officially started your biz.
Word of mouth is the best, cheapest and slowest form of advertising around today.
Stay away from costly advertising if possible. The impatient side of me always wants things NOW, however the reality of being self-employed has taught me a lot, like patience. Self-Employment is a long slow process. You'll find hundreds of free articles to help you stretcher your day and your budget. There's even a free weekly email newsletter.