There's a wide range of how-to and inspirational magazines for painters and artists available, whether you paint with acrylics, oils, watercolors, or pastels, used mixed media, draw, or do collage. There are magazines for artists at all levels, from complete beginners to artists wanting to improve their skills to professionals. I read several (those at the top of this list) for a boost of inspiration and sheer enjoyment of the subject matter.
This remains my all-time favorite painting magazine. Most of it showcases practicing artists from around the world working in different mediums (painting, drawing, and printmaking), with a gallery of their work and, usually, a step-by-step demo. The emphasis is on the artist describing their approach and working process, rather than intricate how-to descriptions. There's a themed competition in each issue (which you can enter on-line), and photos of previous winners and runner's up with information on the artists' inspiration, design strategy, and working process. It's a bi-monthly magazine, giving you plenty of time to read through each issue.
If you're a landscape painter and interested in what other landscape artists are doing -- both results and processes -- then take a look at this magazine, whether you paint on location or not. The focus is mainly USA, but the mediums and approaches is varied. It also has articles on past artists, analyzing their work and process.
French edition), this magazine is mixture of artist profiles and techniques, aimed at intermediate and experienced artists. It's sumptuously illustrated, as you can see in the sample issue on the publisher's website. Inspiring even if watercolor isn't your medium.
This British magazine is the best how-to magazine available, in my opinion, ideal for both beginners and artists wanting to expand their skills. Each month professional artists tackle both drawing and painting subjects, and specific techniques. There usually also a profile of a famous artist or painting, a roundup of events and competitions in the UK, and reviews of art materials.
An American magazine, not to be confused with the UKs "The Artist" (see no 2), though still an inspiring and helpful publication. The focus is practical and how-to; it includes all painting mediums, some drawing-related features, an "ask the experts" Q&A, exhibitions information, and pages of listings of workshops (including some outside the USA).
A&I is a colorful, large format magazine that labels itself as "For everyone inspired by art". It combines profiles and interviews of professional articles with career-related advice, product reviews, demos and technical tips. The focus is on the UK artists and events.
If mixed media and/or collage is your thing, then you'll likely enjoy this magazine which is focused on "artistic discovery" through projects that can use anything and everything. If you like art journaling and pushing the boundaries of where art and craft techniques meet, take a closer look. If you're a fine-art purist who likes only traditional-style painting on canvas, stay away.