To get full access to the site, it is better to register. Registration as a DeviantART member is free but there is an option to purchase premium subscription at $29.95/year. With this premium, you can view the site without any ads, and there are a lots of additional feature that you can get such as pretty journal, and customizable profile page.
Slowly, from time to time, I discovered that I can submit my own work there. You can actually submit almost everything there - photos, digital art, traditional art, sketches, stock photos, wallpapers, skin and themes for various OSes, etc, as long as you are the authorized owner of the artwork - but please bear in mind that you can NOT ever submit other person's work, or you'll be banned by the admin or worse, the community will 'bang' you. There will always be new member there that do not know this rule, and it is good if we can inform them nicely.
1. You can submit almost everything - even literature (poems, short story, etc) if you're really good at that kind of work. You can even submit desktop screen shots if you like. I submitted quite a number of desktop screen shots when I first joined the community, and this is my most favorite of all:
2. Your work can be commented and favourited by the others. You'll be notified for every comment and favourite that you get. Most of the time, if your work is good, it will be appreciated with good feedbacks and a lot of favourites. Even if your work is not good, sometimes you can get good critiques from experts to improve your work further.
3. If you think that your work is good enough that somebody would love to buy it, you can make your work available as print, in which you can sell them online, through DeviantArt itself. All the printing and shipping will be handled by DeviantArt staffs, in which they will get some commission from your sale and you get some parts from the sales - it is clearly pointed out when you submit any of your work as print for sale. I think it is fair enough. You don't really have to give out so much effort, but you can gain something out of it.This is so far my two best seller in the site:
6. You can have your own blog there. It is called journal. I often express my personal opinions in DeviantART journal. It was fun to receive support from unknown person from various countries back then. It feels good to know that we can unite in online world, getting feedback from various persons from variety of personal backgrounds.
7. I like how my submitted photos and digital art (called deviations in the site) are arranged in the site. In fact, you can arrange them the way you like. For free account itself, you can create as many folder as you want inside your own "gallery" online. It is like you have your own portfolio for your work. For subscribers, more options for customization are available. I have to say the premium option is worth it.
I think that's enough. Personally, I never regret joining this site. Feel free to join the site, either for fun or just to spend some leisure time there. :)