I agree; right here on fauna is a good place to advertise while you're still starting out. A website is also a good idea so that people can see what you have to offer.
Be aware though that it may take from 3-5 years to really start to get your name out there, so don't expect it to happen all at once. It takes time to build yourself a reputation. I started breeding in 2006-2007 and wound up selling most of my offspring that year to a local, privately owned pet store. The next year I sold about half to individuals, and then sold the other half to the previously mentioned pet store. The next year, I sold all of my animals to individuals, but I had to keep 2-3 of them until spring (it also helped that I got into breeding my own feeders so it wasn't costing me so much to maintain those animals). This year, I pre-sold a few of my babies once they hatched but before they were officially ready to go, so not everything even made it to my website, which made me happy.

I've still got some babies for sale, but I don't fear having to hang onto them as much as I did the first year when no one knew who I was. Now my name is getting out there, and as someone else already said, word of mouth can be the best form of advertising. But word of mouth can backfire, too; the way you conduct yourself on forums or with your customers will dictate whether or not those customers come back, and what type of word of mouth you receive.
If you're going to breed a particular species,
know that species. Make sure your husbandry is spot on (granted, everyone has quirks that work for them, but make sure you know the basics like the back of your hand) and make sure that you can advise those who buy from you if need be--some will be experienced reptile keepers, but you'll also have some customers that are new to reptiles and will need assistance with cage setups, feeding, etc. If you can provide them with the correct information as well as a healthy animal, they will be much more likely to purchase from you again in the future or to recommend you to their friends.