You cant upload directly without paying a sub to Dan the site owner. Go to your profile and look under Actions (on the left) for Paid Subscriptions.
Instead most people link to other image hosting sites where they put their pics.
I upload my pics to
http://www.imgur.com and link to them from there.
If you want to know more let me know and Ill post more details but it is very easy and there are lots of posts on how to post images..