When I first began painting some 10 years ago, I remember my first trip to my local art supply store. I recall my feeling of utter confusion as I perused the aisles. This particular art store had every tube of paint, brush, medium and canvas known to man, far too many choices for a confused beginner. After several moments, a sales person came by and began to assist me in finding the supplies I needed. To make a long story short, I left the store 30 minutes later with a box full of supplies, half of which I had absolutely no idea what to do with. I wish I knew then what I know now. I could have saved myself a lot of money.
When you are first starting out in oil painting, you shouldn't go overboard on supplies. It's best to start with the basics. When you become more experienced, you can then try out different supplies until you find the items you are most comfortable working with.
Oil Painting Brushes - Brushes come in various sizes and shapes from flats to brights to rounds. They are also available at various prices. Brushes are something you should definitely spend a bit extra on and shoot for quality. You don't want cheap brushes. Cheap brushes are a huge headache mainly because they shed hair and lose their shape quicker than quality brushes. The types of brushes you purchase really depend on the type of painting you plan on doing: landscapes, portraits, impasto work, etc., all call for certain types of brushes. You will only learn this over time as you become more experienced and develop your own style. For starters, I would purchase a few flats of various sizes, a few small rounds for detailed work and a fan for blending. Make sure to also purchase a good brush cleaner and preserver. I use the Marx Brush Care System for cleaning and preserving my brushes and it works great.
Oil Paints - Oil paint also varies in price and quality. There are some very good paints on the market today. I prefer to work with Grumbacher Artist Oils, but Winsor & Newton oil paints are also quite popular. There are different grades of paint. There are student grade paints and professional grades. My own preference is to work with the professional grades, as the colors are more brilliant than student grade paints. I guess it's ok in the beginning to purchase a lesser quality for learning and experimentation. I guarantee once you try the professional grade paints, you will never go back to student grade. This is my opinion of course. Artist color choices vary. Some prefer a limited palette of only a few colors, while others prefer to have a variety of different colors at their disposal.
Here are the colors of my palette. You do not have to buy these exact colors, as this is only my preference that has developed over time.
Cadmium Yellow Light
Cadmium Red Light
Oil Painting Mediums - Medium preference varies greatly from artist to artist. I think every artist has his or her own mixtures and formulas. I myself use linseed and poppy oil. Linseed oil has a tendency to yellow the colors so I do not mix it with my lighter color mixtures. For lighter color mixtures, I use poppy oil as it has less of a tendency to yellow. There are other mediums available. I recommend that you try your own mediums and recommendations from artists until you find something that produces the results you are after.
Canvas and Other Supports - The popular support that many artists work with is cotton canvas, but there are other supports available. Some other choices are linen canvas, boards and canvas paper for instance. You could also buy rolled canvas and stretch your own if desired. This again is something you have to experiment with until you find a support that works best with your style of painting. I recommend starting with a few smaller to medium sized canvases. I work with FREDRIX Red Label Stretched Cotton Canvas. Red Label is a medium textured quality canvas excellent for use with oils and a popular choice amongst oil painters.
Palette - Palettes are made from various materials including glass,wood, plastic, and even paper. My palette of choice is the Bob Ross Clear Palette. This palette is wonderful. It's easy to clean, holds a lot of paint with adequate room to mix your colors. It's also priced quite reasonably.
Easels - Easels are also available in various sizes and price ranges. You will need a good stable easel to paint on; otherwise your canvas will wobble around when you paint. This can be quite frustrating. You also need to decide whether you will be painting primarily in your studio or if you are an outdoor painter. If you are painting outdoors you should consider purchasing a French easel. The Jack Richeson Academy Verona Half French Easel is a good buy. If you work primarily in your studio, then you have a lot of easels to choose from. I personally use a STANRITE 500 Classic Aluminum Easel. It's an excellent easel that is both lightweight and sturdy. It sets up easily and can be folded for easy transport.