Imagine FX is a monthly magazine that is aimed specifically at illustrators. The Magazine comes packed full of usefull tutorials and even comes with a free cd-rom with loads of great video workshops and brushes etc for computer programs, undoubtably though is the sense of community.
Artist can write in with what they're stuggling with and the group of artists that imagine fx has on hand can answer those problems. The magazine also shows other artists work so getting published would be another way to get some great exposure. The Magazine also lists events realted to illustration all across the world, this is a great way to find out about some great events.
Beyond the magazine Imagine FX also has a website where memebers can share critques with each other and post on forums. Much like deviantart this a great way to meet other artists and improve your own skills, the website also offers art challenges on a weekly and monthly basis.
Being a part of this community is a good way to improve skills and meet other artists at the same time, and if you get noticed and published it's a good way to get noticed.