Rock painting CAN be an inexpensive hobby. I am one of those people who say "You can never have enough paint, brushes or books", so what could have been a cheap hobby has turned into a small investment for me, but it doesn't have to be that way, if you have will power!
If your just starting out and on a budget, you can get by with the basics
A smooth rock you found or bought
A cup or container of water to rinse your brushes and thin the paint
One of Lin Wellfords' rock painting books is very helpful but not required
Newspaper to cover your work area or some kind of cleanable surface
Paper towels or napkins to wipe your brushes on
A table or some kind of work surface to paint on
That's all you need!
Watch out, rock painting is addicting and you might find yourself buying more and more painting related items to make your rock painting easier or better. I love painting books of all kinds. See my Books link for my personal favorites. I am getting a HUGE collection of them. I also keep buying more and more colors of paint. Although you can mix basic paint colors to get more colors, I would rather buy the color already mixed for me. I also buy alot of brushes. I'm still trying different brushes to see which ones I like the best.
To Save Money wait until your local craft store has a sale. Michael's and Jo Ann's Fabrics have coupons running in the newspapers. I bought most of my books, paint and brushes with 40% off coupons. I also buy alot of books off of e-Bay.
These are the brushes that I use the most.
*The two on the right are cheap, stiff brushes for painting rough rocks
*Next to them are a variety of flat brushes I use to cover large areas on smooth rocks or to make a nice edge.
*The two red brushes in the middle are just for small areas of detail
*The purple brush is a fan brush for different textures and fur
*Green brush is an angle shader I used on the daisy plant
*The next four are different size liners or script liners for thin detail
*The last two on the left are scrubber brushes, like the big stiff brushes, they are good for scrubbing paint into a rock. One is rounded and the other is a flat shape.
You can buy the brushed individually or by the variety package. A package of flats and a package of rounds should get you going. If you can buy a package with a 40% off coupon you will really save money. Remember you don't have to get the really expensive brushes for rocks. I would however get a good liner brush like a O size for detail. I use that brush alot.
For most things you will want to draw the basic design on your rock before you start painting. You can use regular chalk (left of picture) or a penil. I prefer soap stone. (right of picture) Get them at a welding supply place. Like chalk they erase easy. They make a thinner line than chalk. You can get an optional holder it fits into. I don't use a marking pen to make the lines as they show thru the paint sometimes. I do use a thin Zig (for scrapbooking) or Sharpie to sign and date my rocks on the bottom. Other markers are just too thick.
These are much better than just a container of water. They won't tip over and spill. They have a place to hold your brushs and the bottom has ridges that you use to run your brush across to help clean the paint out of them. This one is getting pretty old and ugly but it works great. They come in different sizes and styles.