Sure! DeviantART is an art community where you can post your own works, while also taking a look at the works of many others
If people decide to comment on your works you can receive some constructive criticism that might help you to improve yourself. If you get a "watch" someone decided to follow you, and get futere updates
Then there are tons of ressources to help you out if you want to improve on a special thing. The very best works of the communnity will be rewarded a Daily Deviation. They are suggested by community members such as you and me
There also are contests and such, either hold by DA itself or by one of many groups you can join. This basically is a round-up on the most important facts, I guess, so should you have more in-depths questions just tell me, and I'll help you out gladly