Learning to paint with oils can be one of the most rewarding forms of artistic expression you could ever experience. The unique qualities of the medium allow an artist to experiment with many different techniques which can be learned by painters of all skill levels. Just set your fears aside, pick up your brush, and make that first brush stroke on the canvas. Don't worry about painting a masterpiece the first time out, just be willing to learn.
Have you ever seen "The Joy of Painting" featuring artist Bob Ross? His soft spoken demeanor and free spirit draw you into his world, and make you believe that anyone could paint if they'd just pick up the brush and try. How many of us have been amazed how he forms a perfect tree with just a few brush strokes, or how he always finished his masterpieces in thirty minutes or less? Is it really that easy?
Yes...and no.
Yes, you could probably learn to paint reasonably well with a few good how-to books, or with something like the Bob Ross painting series. If you were to learn the basics of oil painting, and have a little patience, I'm sure it wouldn't be long before you could paint something that wouldn't embarrass the family if it was hung in the living room in a conspicuous place.
Could you learn to paint like Monet in a year or two with steady practice? Probably not. Learning the basics such as color mixing, oil mediums, design, and brushwork can take many years to master. Chances are you will have spent quite a bit of money in canvas, paint, brushes, and other necessary supplies before you even paint something that you didn't have the urge to throw in the trashcan. Oil painting supplies aren't cheap, so I suggest you start with one of those ready-made oil painting starter kits, just to see if you even like painting with oils; and start on a very small canvas!
Why do you want to paint? Do you think your paintings could sell for a million dollars at a Christie's auction? I'm afraid that even if you were that good, most art collectors seem to prefer masterpieces painted by dead artists, so don't get your hopes up. Until you master the medium, I suggest painting for the sheer pleasure of it.
I've painted with both traditional techniques, and with wet-on-wet techniques favored by the impressionists. Traditional oil painting requires using paint mixed with mediums applied in thin layers until you achieve the desired result. This is very time consuming, and takes many years of practice and training to perfect. Because of the lengthy process, it's very difficult to recoup the time you put into the paintings if you were wanting to sell them for a profit.
My technique of choice is wet-on-wet. This is the style that painters like Bob Ross use, and is the style I'd recommend for beginning artists. There's no need for mediums, because you're using paints straight from the tube. You can achieve results quickly, which can keep beginning painters from getting discouraged. Wet-on-wet is a loose style of painting that unleashes feelings, emotions, and spontaneous creativity.
You don't need every color under the sun to get started. Every color combination you can think of comes from primary and secondary colors mixed with each other, and with black and white. Most how-to books can tell you exactly what colors to start with. When you gain experience you may want to invest in certain colors that you prefer straight out of the tube. Start with a small selection of brushes, and then experiment with different types of brushes and painting knives when you gain a little more experience. Start with smaller canvases and work your way up. Study the work of other artists and be open to constructive criticism.
Most of all, have fun! Remember that oil painting should be something you enjoy. It's not about perfection, it's about communication. Paint something that says something to you, and by doing that, you'll be certain that your art will speak to others. I've made some money selling my art, but I love painting so much I'd do it for free; just don't tell anybody. Good luck and happy painting!