Create your image then when it's ready create a new thread and put something like "May Challenge Entry" in the subject line. Agentsmith will go throught the forum as he sees them posted and collect them. Near the end of the month he usually posts a warning that you have so much time left to get the entries in then he'll create a thread that says something about May's challenge voting and the link to the page with all the entries will be in that thread. Go to the link the go back to the thread to post your votes.